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NMR istraživanje kvantne kritičnosti u Ce3Pd20Si6 i m-PhNO2BNO sustavima
No full textThe studied heavy fermion Ce3Pd20Si6 (CPS) and the quantum magnetic m-PhNO2BNO (BoNO) systems feature a rich phase diagram at low temperatures due to competing electronic interactions. This NMR/NQR study reveals the microscopic structure of magnetically ordered phases and characterises the quantum phase transitions (QPTs). Both systems can be driven through quantum critical points (QCPs) using an external magnetic field, with similar effects observed in other systems under hydrostatic pressure or doping. Near the QCP, strong quantum fluctuations lead to the formation of quantum critical matter, hypothesised to have a universal description. With two distinct cerium magnetic moments in CPS, antiferroquadrupolar (TQ = 470 mK) and antiferromagnetic (TN = 250 mK) orders are observed at low temperatures. Neutron scattering research links the magnetic activity to cerium moments at the Ce(8c) position, and CPS shows a Kondo-breakdown QCP, where magnetic order suppression coincides with Fermi surface reconstruction. We investigated CPS using 105Pd NQR and 29Si NMR, determined the quadrupolar coupling parameters νQ and η, and found no conventional magnetic order down to 70 mK. However, temperature-dependent relaxation rates suggest the presence of two Kondoscreening energy scales, with no sign of quantum criticality at low temperatures, implying an unobserved magnetic order between Ce(4a) moments. BoNO, an organic biradical, forms an effective S =1 Haldane state, confirmed by bulk magnetisation and X-band EPR measurements. We investigated its magnetic field-induced long-range ordered (LRO) phase using 1H NMR, determining critical exponents consistent with a 3D-XY antiferromagnetic QPT (ν = 2/3). In the gapless phase, nuclear relaxation rates align with the Tomonaga-Luttinger liquid model. The staggered magnetic moment evolution in the LRO regime matched the mean-field and Quantum Monte Carlo (QMC) predictions, though slight discrepancies suggest magnetostriction effects under an external magnetic field. Finally, we compared BoNO with other field-induced Bose-Einstein condensate systems and used the standard scaling relations to describe quasiparticle behaviour in the quantum critical region.U ovom su radu istraživani spojevi iz klase sustava teških fermiona i kvantnih magneta, Ce3Pd20Si6 (CPS) i m-PhNO2BNO (BoNO). Proučavana je njihova struktura, struktura magnetski uređenih faza, spinska dinamika i priroda uočenih faznih prijelaza. Kvantni fazni prijelazi (KFP) pojavljuju se pri temperaturama od T = 0 K kada zbog suprotstavljenih elektronskih interakcija sustav mijenja svoje osnovno stanje. KFP proučavani u ovom radu mijenjaju osnovno stanje sustava iz magnetski uređenoga (antiferomagnetskog) u neuređeno paramagnetsko i/ili metalno stanje (Fermijeva tekućina). Tehnikom nuklearne magnetske i kvadrupolne rezonancije okarakterizirana su magnetski uređena stanja u ovim sustava, te kvantni fazni prijelaz kada primjenom vanjskog magnetskog polja sustave tjeramo kroz kvantnu kritičnu točku (KKT). U sličnim sustavima kvantni fazni prijelazi su također inducirani primjenom hidrostatičkog tlaka ili kemijskog dopiranja. Univerzalni teorijski opis kvantno kritičnog ponašanja u blizini KKT neovisan je o eksperimentalnoj realizaciji (tj. uzorku) kvantnog magnetskog sustava. Poznato je da takav univerzalni opis ovisi isključivo o dimenzionalnosti sustava i prirodi osnovnih stanja (magnetsko uređenje, orbitalno uređenje) s obje strane KKT
Commercial relations of Bosnian Eyalet and Dubrovnik Republic from 1645 to 1699
No full textDoktorski rad Trgovački odnosi Bosanskog ejaleta i Dubrovačke Republike od 1645. do 1699. godine bavi se u prvom redu trgovačkim i gospodarskim vezama Bosne i Dubrovnika sredinom i tijekom druge polovine 17. stoljeća. Osim toga, obrađuju se opće prilike toga vremena u Bosanskom ejaletu i Dubrovačkoj Republici, kao i sigurnosni izazovi koji su imali ogroman utjecaj na bosansko-dubrovačke odnose, a prvenstveno na trgovinu. Vrijeme velikih i dugih ratova, Kandijskog (1645.-1669.) i Bečkog (1683.-1669.) rata, trajalo je najvećim dijelom tijekom ovog razdoblja, što je utjecalo na slobodu kretanja ljudi i roba, te opću sigurnost na putovima Bosanskog ejaleta i Dubrovačke Republike. Osim toga, utjecalo je i na odnose Bosne i Dubrovnika prema drugim državama na prostoru Balkana. U ovom se razdoblju dogodio i dubrovački potres 1667. godine, koji je imao znatnog utjecaja na Dubrovačku Republiku, ali i susjedne zemlje - Osmansko Carstvo i Mletačku Republiku.
Tijekom ovog razdoblja bosansko-dubrovačka trgovina je bila pod utjecajem odnosa između velikih sila, prvenstveno Osmanskog Carstva i Mletačke Republike. Odnos između ovih aktera izravno ili neizravno bio je okidač za probleme u odnosima Bosne i Dubrovnika. Ipak, i u takvim teškim okolnostima, Bosna i Dubrovnik su očuvali kontinuitet trgovačke i gospodarske suradnje koji je trajao od srednjeg vijeka. U razdoblju od 1645. do 1669. godine, trgovački odnosi su oscilirali od vrlo uspješnih u prvim godinama Kandijskog rata, stabilnih tijekom razdoblja mira od 1669. do 1683. godine, pa do rijetkih i gotovo prekinutih nakon 1683. i mletačke blokade u zadnjoj deceniji 17. stoljeća. U radu smo predstavili odlike sva tri razdoblja, stavljajući u prvi plan trgovačke odnose između Bosne i Dubrovnika.The doctoral thesis “Commercial relations of the Bosnian Eyalet and the Dubrovnik Republic from 1645 to 1699” deals with trade and economic relations between Bosnia and Dubrovnik in the middle and second half of the 17th century. In our research, we also dealt with the challenges and circumstances of that time in Ottoman Bosnia and Dubrovnik, as well as the security problems that had a huge impact on Bosnian-Dubrovnik relations, primarily on trade. During the great wars that lasted from 1645 to 1669 and from 1683 to 1699, the economy suffered various impacts and faced great challenges. Also in this period there was a great earthquake in Dubrovnik that happened in 1667. This disaster had a significant impact on the Dubrovnik Republic, but also on the neighboring countries, the Ottoman Empire and the Venetian Republic. During this period, Bosnian-Dubrovnik trade was influenced by mutual relations between the Ottoman Empire and the Venetian Republic. But even in these difficult circumstances, Bosnia and Dubrovnik continued the trade and economic cooperation that had lasted since the Middle Ages. During the Candian or Cretan War (1645-1669) between the Ottoman Empire and the Venetian Republic, Dubrovnik was the main Ottoman port in the Balkans. Various commercial products were imported and exported through the port of Dubrovnik. The interruption of the Ottoman trade with the Venetians and their ports in the middle of the 17th century increased the income of the Dubrovnik residents for several times. But despite the benefits that Dubrovnik had at that time, the territory of the Dubrovnik Republic was often the place of direct conflict among Ottoman and Venetian military units. This resulted in loss of human lives, as well as destruction and material damage. After the earthquake that happened in Dubrovnik in 1667, the economic relations between the Bosnian Eyalet and the Dubrovnik Republic were in decrease. Apart from the earthquake, this fallout was influenced by other factors such as the Venetian-Ottoman peace in 1669, which enabled the return of Venetian trade to Bosnia and the Ottoman Empire. In addition, the strengthening of local merchants in the Bosnian Eyalet significantly reduced the influence of Dubrovnik. The period of stability lasted less than 15 years, so in 1683 the Balkans entered a new period that had a significant impact on the economy and Bosnian-Dubrovnik relations- the Great Vienna War.
The doctoral thesis has six chapters: I. Bosnian Eyalet in the 17th century, II. Dubrovnik Republic in the 17th century, III. Ottoman Empire and Dubrovnik, IV. Economic relations of the Bosnian Eyalet and the Dubrovnik Republic from 1645 to the end of 1669, V. Bosnia and Dubrovnik between the Candian War and the Vienna War (1669-1683) and the VI. Bosnian-Dubrovnik relations during the Vienna War (1683-1699).
In the first and second chapters, we dealt with the general situation in the Bosnian Eyalet and the Dubrovnik Republic during the 17th century. The first chapter: Bosnian Eyalet in the 17th century, has two subchapters that talk about general and economic conditions in Bosnia. As one of the provinces of the Ottoman Empire, the Bosnian Eyalet was an integral part of the Ottoman economic space, where all the economic problems of this empire were more or less felt. The head of the province (eyalet) was the beglerbey, and below him were the sanjakbeys. At the time of the beginning of the Candian War in 1645, the Bosnian Eyalet had seven sanjaks: Bosnia, Herzegovina, Zvornik, Klis, Pakrac-Cernica, Krka-Lika and Bihać. In this period, the most important economic and trade centers were Sarajevo, Mostar, Banja Luka, Foča, Novi Pazar, Pljevlja and Livno. During most of the first half of the 17th century, the official residence of Bosnian governors was in Banja Luka. After 1639, and before 1655, the official seat of the Bosnian beglerbeys was transferred from Banja Luka to Sarajevo. During this period, the security situation was a great challenge for the authorities of this province. Bandits (hayduks) and their groups robbed on the roads, which mostly affected merchants and their goods. During the first half of the 17th century, local merchants in Bosnia grew stronger, while the influence of Dubrovnik merchants significantly declined. The Candian War had an adverse effect on the economy of the Bosnian Eyalet, which particularly affected Sarajevo as a major commercial center, leading to stagnation in the second half of the 17th century.
Chapter Dubrovnik Republic in the 17th century talks about the general situation in Dubrovnik during this century. In this chapter, there are two subchapters, and they talk about the socio-economic trends in the Republic at that time, as well as the consequences of the 1667 earthquake. According to some researchers, the Dubrovnik Republic had about 35,000 inhabitants from the middle of the 16th to the first years of the 19th century, while the city of Dubrovnik itself had between 5,000 and 7,000 inhabitants. In 1642, about 38,700 people lived on the territory of the Dubrovnik Republic. After the earthquake in 1667, the number of inhabitants was significantly reduced. In the 1673/74 census, around 25,000 inhabitants were recorded in the territory of the Republic, while only 1,300 inhabitants were registered within the city of Dubrovnik. In total, with the suburbs of Pile, Ploče, Gruž and Bosanka, the city had 4,218 inhabitants. The beginning of the Candian War in 1645 led to the turning of Ottoman trade from the Venetian ports to Dubrovnik. The port of Split was no longer an option for Ottoman traders. Therefore, the port of Dubrovnik experienced a great growth like in the 16th century. The value of trade goods exported from the Ottoman Empire to Dubrovnik was up to 200,000 gold coins on an annual level. This economic prosperity of the port of Dubrovnik lasted until the earthquake in 1667. Two years later, the Candian War ended. After the end of this war, the trade of Bosnian merchants through the port in Split continued again, but not with the same intensity as before 1645. During this period, Dubrovnik had to diplomatically balance between the Venetian Republic and the Ottoman Empire. The consequences of this war directly affected the territory of Dubrovnik. Venetian soldiers used the territory of the Dubrovnik Republic for offensives towards Ottoman territory, which provoked reactions from the Ottomans.
The third chapter Ottoman Empire and Dubrovnik deals with the relations between the Ottomans and the people of Dubrovnik. The three subchapters from this part of the text talk about the relations between the Dubrovnik authorities and the central authorities of the Ottoman state in Istanbul, relations at the local level with the authorities of the Bosnian Eyalet and economic relations between Bosnia and Dubrovnik. Ottoman and Dubrovnik citizens were connected by business and economic relations for centuries. During the 17th century, some inhabitants of Sarajevo kept more valuable things and money in Dubrovnik. They considered that city and its people safe and reliable. Doctors from Dubrovnik had a good reputation, which is why the Ottoman officials and other prominent people in the Bosnian Eyalet invited them for treatment. The Ottomans came to Dubrovnik, and many merchants from Dubrovnik lived in the Ottoman Balkan regions. In the period between 1520 and 1620, 1,977 Dubrovnik merchants traded and worked in the Balkans. Economic relations between Bosnia and Dubrovnik were particularly frequent in the border areas. Small local squares in these areas were meeting places for Ottoman and Dubrovnik residents. Various food products, fruits and vegetables were traded on them. In the fourth chapter, we deal with the economic relations between the Bosnian Eyalet and the Dubrovnik Republic from 1645 to the end of 1669. This chapter has five subchapters and deals with the security situation during the Candian War and trade and economic relations between Bosnia and Dubrovnik in this period. The import of salt and other goods from Dubrovnik to Bosnia is presented in more detail. We also write about the export of leather, wax and wool, as well as trade in livestock, grain and food items from 1645 to 1669. Various bandit or hayduk groups, mainly with the support of the Venetians, threatened the normal flow of people and capital. The danger also came from the local Ottoman authorities, most often from the city of Novi (Herceg Novi) who considered Dubrovnik responsible for the crossing of bandits towards to the Bosnian Eyalet and creating chaos in the border area. The reactions of people from Novi were often not without reason, because some of the people of Dubrovnik had a positive view of the Venetian struggle against the Ottomans, and some of them went to the hayduks themselves. Because of this, during the Candian War many caravans and trade goods were stolen and looted, and human lives were lost. Nevertheless, economic interest established connections between opposing parties. Dubrovnik, with its neutral position, played a key role in the departure of Ottoman merchants and their goods to the cities of the Apennine peninsula, and even to Venice. The chapter Bosnia and Dubrovnik between the Candian War and the Vienna War (1669-1683) has two subchapters. They deal with the general security and economic conditions between Bosnia and Dubrovnik during the short period of peace that lasted 14 years. The end of the Candian War in 1669 brought the Venetian port in Split back into focus, as well as the Venetian merchants as rivals in trade with the Bosnian Eyalet. This was especially felt in Dubrovnik's loss of the monopoly on the sale of salt in Gabela, which the people of Dubrovnik had kept for centuries. Regardless of the diplomatic activities in Istanbul and the European states, the people of Dubrovnik lost this diplomatic battle with the Venetians at the end of 1673. The Grand Vizier decided that Venetian salt go to Gabela by sea, and the Dubrovnik salt by land for sale in Bosnia. Because of this, after several centuries, the people of Dubrovnik lost the salt market in Gabela. During that time of short peace, regular trade continued between Bosnia and Dubrovnik. Leather, wax and wool were exported from Bosnia, and fabrics and other products from Europe were imported from Dubrovnik.
The last and sixth chapter Bosnian-Dubrovnik relations during the Vienna War (1683-1699) has three subchapters that talk about general conditions, security and economic cooperation during this war. Venice's entry into the war in 1684 reopened earlier problems from the time of the Candian War. The Ottoman Empire suffered heavy defeats in the first years of this war. At one point, the Bosnian Eyalet was almost completely surrounded and cut off from the rest of the Ottoman territory. This led to trade interruptions for import and export goods between Bosnia and Dubrovnik. Trade between Bosnia and Dubrovnik was localized to the border areas and decreased. Venetian expansion around Dubrovnik also threatened the existence of this Republic. The Venetian conquest of the strategically important place Carina at the end of 1687, and its complete blockade in 1690, were a huge blow to the Dubrovnik-Bosnian trade. An important route to the Bosnian Eyalet was cut off, and the Venetians held the city of Dubrovnik in a naval blockade. However, even then trade was not completely interrupted because the people of Dubrovnik found ways to trade through the port in Slano. However, every caravan was in danger from the Venetian military units. Despite the war, the Venetians, Ottomans and Dubrovnik tried to establish trade corridors in the last decade of the 17th century. Negotiations on the opening of the Venetian ports in Novi, Risan and Neretva did not lead to a solution, which is why the revival of Bosnian-Dubrovnik trade had to wait until the end of the Vienna War in 1699.
The period from 1645 to 1699 in the context of trade can be seen as a time of instability caused by many factors. Since the beginning of the 17th century, Dubrovnik's trade has been in a recession. In addition to the fact that the center of world trade was transferred from the Mediterranean to the Atlantic, which significantly affected the Dubrovnik navy, there was also a strengthening of local traders in the Bosnian Eyalet, and competition from the Venetian port in Split. The trading colonies of Dubrovnik gradually decreased. Finally, an earthquake occurred in 1667. Between the beginning of the war in 1645 and the earthquake in 1667, there were periods that reminded us of the golden age of Dubrovnik.
In the period after 1669, there was an opening of trade routes, but also renewed Venetian competition for the Ottoman trade in the Balkans. During the last two decades of the 17th century, trade activity experienced a rapid decline due to the war, and was mainly reduced to local contacts in the border areas. Bosnian-Dubrovnik trade was often a victim of relations between the great powers, which was exactly what happened during the Candian War and Vienna War. Despite this, in the second half of the 17th century, Bosnia and Dubrovnik preserved the continuity of economic cooperation built since the Middle Ages. Even in the times of the most difficult blockades, such as the Ottoman trade bans (yasak) from the middle of the 17th century and the total Venetian blockade of Dubrovnik after 1690, merchants found ways to cooperate and transfer trade goods
CD56-positive NK cells and CD138-positive plasma cells in the basal decidua and histopathological characteristics of placentas after treatment of the endometriosis-related infertility
No full textUvod: Endometrioza je kroničan, estrogen-ovisan poremećaj povezan s neplodnošću, ponajprije zbog štetnog učinka na ovarijsku rezervu i receptivnost endometrija. Slično ektopičnim endometriotičnim lezijama, eutopični endometrij kod endometrioze pokazuje izmijenjene imunološke odgovore, uključujući poremećen broj prirodnoubilačkih stanica (NK) i plazma stanica. Postupci medicinski potpomognute oplodnje (MPO) predstavljaju mogućnost liječenja neplodnosti kod zahvaćenih žena, no dostupna literatura ukazuje na višu učestalost nepovoljnih perinatalnih ishoda u trudnoćama s endometriozom. Ipak, histopatološke značajke posteljice i imunološki odgovori u trudnoćama kod pacijentica s neplodnošću uzrokovanom endometriozom, a koji mogu pridonijeti tim ishodima, nisu dovoljno istraženi. Cilj: Cilj ove disertacije bio je istražiti histopatološke promjene posteljica, uz analizu ukupnog broja CD56-pozitivnih NK stanica i CD138-pozitivnih plazma stanica u uzorcima bazalne decidue (BD) jednoplodovih trudnoća nakon liječenja neplodnosti uzrokovane endometriozom. Sekundarni ishodi uključivali su učestalost perinatalnih komplikacija te povezanost faktora endometrioze s brojem imunoloških stanica decidue i histopatološkim karakteristikama posteljice. Materijali i metode: Ova disertacija objedinjuje rezultate dviju monocentričnih istraživanja slučaja i kontrola, koje su obuhvatile histopatološku analizu posteljica te imunohistokemijsku (IHC) analizu CD56 i CD138 biljega u BD uzorcima trudnoća nakon liječenja neplodnosti uzrokovane endometriozom, muškog faktora neplodnosti te fizioloških trudnoća. Minimalna potrebna izračunata veličina uzorka iznosila je 91 posteljicu. Lezije posteljice kategorizirane su prema Amsterdamskom konsenzusu o patologiji posteljica te su podijeljene u anatomske, upalne, lezije vilozne zrelosti i poremećaje vaskularne perfuzije. IHC analiza provedena je primjenom primarnih monoklonskih mišjih protutijela za CD56 i CD138, uz sekundarna protutijela prema standardiziranom protokolu. CD56 i CD138 pozitivne stanice prijavljene su kao ukupan broj stanica po 1 mm² BD uz pomoć mikroskopa Olympus BX46 i Olympus Image Analyzer sustava. Rezultati: U istraživanja je bilo uključeno 107 sudionica s terminskim posteljicama, raspoređenih u tri skupine: MPO Endometrioza (n=36), MPO muški čimbenik (n=31) i fiziološke trudnoće (n=40). Posteljice iz trudnoća s endometriozom pokazale su veću učestalost posteljičnih lezija u odnosu na kontrolne skupine, uključujući pojačano stvaranje sincicijalnih čvorova, skraćene pupkovine i višu učestalost poremećaja vaskularne malperfuzije (subkorijalno i perivilozno taloženje fibrina, interviloznu trombozu te fetalnu vaskularnu malperfuziju visokog stupnja). U prilagođenom regresijskom modelu čimbenik endometrioze bio je povezan s pojačanim stvaranjem sincicijalnih čvorova i hipertorzijom pupkovine. Trudnoće povezane s endometriozom imale su veću učestalost krvarenja u ranoj trudnoći i prijetećeg prijevremenog porođaja, kao i veću stopu carskih rezova te češću pojavu novorođenčadi s najnižom porođajnom masom. Uzorci BD posteljica iz trudnoća s endometriozom pokazali su najnižu medijalnu vrijednost CD56-pozitivnih NK stanica u usporedbi s kontrolnim skupinama, pri čemu je njihova smanjena prisutnost bila povezana s određenim posteljičnim lezijama (nezrelost resica, vilitis nepoznate etiologije niskog stupnja, intervilozna tromboza i pojačano perivilozno taloženje fibrina). S druge strane, nisu uočene značajne razlike u broju CD138-pozitivnih plazma stanica između ispitivanih skupina. Zaključak: Dobiveni rezultati upućuju na moguću izmijenjenu imunološku reakciju majke, temeljenu na sniženoj infiltraciji NK stanica, što može otežati pravilnu invaziju trofoblasta, remodeliranje spiralnih žila miometrija i razvoj posteljice, a čime je kompromitirana posteljična perfuzija koja pridonosi nepovoljnim perinatalnim ishodima u trudnoćama nakon liječenja neplodnosti uzrokovane endometriozom. S druge strane, adaptivna imunost, predstavljena infiltracijom plazma stanica, nije prikazana značajnom u patogenezi endometrioze. Uočeni poremećaji posteljične perfuzije naglašavaju potrebu za povećanim nadzorom funkcije posteljice u trudnoćama nakon MPO liječenja neplodnosti uzrokovane endometriozom. Buduća istraživanja trebala bi biti usmjerena na otkrivanje molekularnih mehanizama endometrioze na disfunkciju posteljice i razvoja perinatalnih komplikacija. Identifikacija potencijalnih biomarkera ili terapijskih intervencija usmjerenih na poremećaj imunološkog odgovora i vaskularno remodeliranje mogla bi poboljšati ishode trudnoća s endometriozom.Introduction: Endometriosis is a chronic, estrogen-dependent condition linked to infertility, primarily due to its detrimental effects on ovarian reserve and endometrial receptivity. Comparable to ectopic endometriotic lesions, the eutopic endometrium in endometriosis patients shows exhibits immune response irregularities, including alterations in natural killer (NK) and plasma cell activity. Assisted reproductive technology (ART) offers a viable fertility treatment for these patients, yet literature show endometriosis pregnancies are associated with a heightened risk of adverse perinatal outcomes. Despite this, here remains a data scarcity on the histopathologic characteristics of placenta and immunological responses in term pregnancies of patients with endometriosis-related infertility, which could contribute to these adverse outcomes. Aim: This dissertation aimed to explore histopathologic alterations of term placentas, and to investigate total counts of CD56-positive NK cells and CD138-positive plasma cells in the basal decidua (BD) samples in singleton pregnancies after ART treatment of endometriosisrelated infertility. Secondary outcomes encompassed the incidence of perinatal complications and examining the potential relationship of endometriosis factor on the decidual immune cell counts and placental pathology. Materials and methods: This dissertation integrates data from two case-control studies which provided placental histopathologic examination alongside immunohistochemical (IHC) analysis of CD56 and CD138 immune cell markers in term BD samples from pregnancies after ART treatment of endometriosis-related infertility, male factor infertility and physiological pregnancies. The minimum required samples size was calculated to be 91 placentas. Placental lesions were reported according to the Amsterdam Placental Workshop Group Consensus as anatomic, inflammatory, villous maturation and vascular malperfusion disorders. IHC study was conducted using primary monoclonal mouse antibodies for CD56 and CD138, followed by secondary antibody application under a standardized protocol, while CD56 and CD138 positive cells were quantified as the total cell count for each studied antibody per 1 mm² of BD (Olympus BX46 and Olympus Image Analyzer). Results: Studies examined term placentas with BD of 107 participants, according to ART Endometriosis (n=36), ART Male factor (n=31) and Physiological (n=40) pregnancies’ group. Endometriosis placentas yielded higher incidence of placental lesions compared to control groups including increased syncytial knot formation, shortened placental cords, and a higher frequency of vascular malperfusion disorders (subchorionic and perivillous fibrin deposition, intervillous thrombosis, and high-grade fetal vascular malperfusion). Endometriosis factor was associated with increased syncytial knots’ formation and placental cord hypercoiling in adjusted regression model. Endometriosis pregnancies experienced higher number of early pregnancy bleeding and imminent preterm labor events, as well as higher cesarean delivery with newborns frequently presenting with lowest birthweight. The BD from endometriosis placentas exhibited the lowest median CD56-positive NK cells’ count compared to control groups, associated with odds for several placental lesions (immature villous ramification, low grade villitis of unknown etiology, intervillous thrombosis and increased perivillous fibrin). Conversely, no significant differences were observed in CD138-positive plasma cell counts across the study groups. Conclusions: These findings could suggest potential impaired maternal immune response based on altered NK cell infiltration, which may hinder proper trophoblast invasion, vascular remodeling and placental development, with compromised placental perfusion contributing to adverse perinatal outcomes in pregnancies after ART treatment of endometriosis-related infertility. However, adaptive immunity with plasma cell infiltration did not show potential influence associated with endometriosis pathogenesis. The observed placental malperfusion lesions highlight the need for increased surveillance of placental function in pregnancies complicated by endometriosis, even in cases conceived through ART. Future research should aim to elucidate the molecular pathways linking endometriosis to placental dysfunction and perinatal complications. Identifying potential biomarkers or therapeutic interventions targeting immune dysregulation and vascular remodeling in endometriosis-related pregnancies may improve maternal and fetal outcomes
THE EFFECT OF THERAPY WITH CONTINUOUS POSITIVE AIRWAY PRESSURE ON THE RECOVERY OF COCHLEAR RECEPTOR CELLS IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA
No full textCilj istraživanja: Cilj je ovog istraživanja bio utvrditi povezanost opstrukcijske apneje u spavanju i funkcije receptorskih stanica pužnice te mogućnosti njihovog oporavka primjenom kontinuiranog pozitivnog tlaka u dišnim putevima.
Nacrt studije: Ovo je istraživanje ustrojeno kao prospektivna kohortna studija u kojoj su izvor informacija bili rezultati audioloških testova na oba uha te upitnici STOP-BANG i Epworthova ljestvica pospanosti. Studija je podijeljena u dva dijela. U prvom su dijelu sudjelovale dvije skupine ispitanika: ciljna skupina oboljelih od opstrukcijske apneje i kontrolna skupina bez apneje. U drugom dijelu istraživanja uspoređeni su rezultati kod ispitanika ciljne OSA skupine nakon 6 mjeseci primjene terapije kontinuiranim pozitivnim tlakom u dišnim putevima.
Ispitanici i metode: U istraživanju je sudjelovalo ukupno 72 ispitanika podijeljenih u dvije skupine. Kontrolnu skupinu je činilo 30 ispitanika, a ciljnu 42 ispitanika. U prvom dijelu istraživanja uspoređivane su vrijednosti audioloških testova tonske audiometrije (TADG), timpanometrije (Ty), ispitivanja slušnih evociranih potencijala (ABR) i otoakustičke emisije (TEOAE i DPOAE) i vrijednosti upitnika STOP-BANG i Epworthova ljestvica pospanosti između ciljnje i kontrolne skupine. U drugom dijelu istraživanja uspoređivane su vrijednosti tonske audiometrije, timpanometrije, otoakustičke emisije i rezultati upitnika Epworthove ljestvice pospanosti u ispitanika ciljne OSA skupine nakon 6 mjeseci primjene terapije kontinuiranim pozitivnim tlakom u dišnim putevima.
Rezultati: Nema značajne razlike u ukupnom pragu sluha između kontrolne i ciljne OSA skupine. Ispitanici ciljnje OSA skupine imaju viši prag sluha samo na 1000 Hz u odnosu na ispitanike kontrolne skupine. Rezultati u TEOAE i DPOAE su pokazali niže vrijednosti SNR u ciljnoj OSA skupini u odnosu na kontrolnu skupinu na svim ispitivanim frekvencijama. Ispitanici ciljne OSA skupine imali dulje latencije I vala i intervalne latencije I – V vala u odnosu na ispitanike kontrolne skupine , no i dalje u referentnim vrijednostima. Nema značajne razlike u pragu sluha po specifičnim frekvencijama nakon primjene CPAP terapije u trajanju od šest mjeseci. Postoji značajna razlika u vrijednostima tlaka u srednjem uhu nakon CPAP terapije. Nema značajne razlike u rezultatima SNR u TEOAE i DPOAE niti na jednoj frekvenciji nakon primjene CPAP terapije u trajanju od 6 mjeseci. Nema značajne razlike u rezultatima praga sluha po specifičnim frekvencijama ovisno o suradljivosti ispitanika u liječečnju. Nakon provedene terapije, kod ispitanika ciljne OSA skupine ovisno o suradljivosti postoji značajna razlika u vrijednostima SNR u TEOAE na 2 kHz i 4 kHz, gdje su one više u suradljivih, dok na ostalim frekvencijama nema značajne razlike. Postoji značajna razlika u rezultatima SNR u DPOAE, više su kod suradljivih na 1000, 6000, 7000 i 8000 Hz. Rezultati u TEOAE nakon provedene terapije su pokazali više vrijednosti SNR na svim ispitivanim frekvencijama osim na 2 kHz kod ispitanika mlađih od 50 godina. Rezultati u DPOAE nakon provedene terapije su pokazali više vrijednosti SNR na svim ispitivanim frekvencijama. Nema značajne razlike u vrijednostima SNR u TEOAE i DPOAE nakon provedene terapije ovisno o prisutnosti povišenog krvnog tlaka i šećerne bolesti tip 2.
Zaključak: Kod oboljelih od opstrukcijske apneje u spavanju postoji receptorsko oštećenje sluha. Primjena kontinuiranog pozitivnog tlaka u dišnim putevima kao terapije OSA-e ne utječe na oporavak receptorskih stanica pužnice. Primjena CPAP terapije dovodi do povišenja tlaka u srednjem uhu. Oboljeli mlađi od 50 godina imaju bolju funkciju receptoskih stanica pužnice nakon terapije u odnosu na starije od 51 godinu. Suradljivost u liječenju CPAP-om ne utječe na prag sluha, no utječe na receptorsku funkciju pužnice gdje je ona bolja u višim frekvencijama kod suradljivih. Prisutnost komorbiditeta ne utječe na receptorsku funkciju pužnice.Objective: To determine the connection between obstructive sleep apnea and the function of cochlear receptor cells, as well as the possibility of their recovery using continuous positive pressure in the airways.
Study design: this study was organized as a prospective cohort study. The source of information were the results of audiological tests on both ears and the STOP-BANG questionnaire, as well as the Epworth sleepiness scale. The study is divided into two parts. In the first part, two groups of respondents participated: the target group was patients with obstructive sleep apnea and the control group was patients without sleep apnea. In the second part of the study, the results of OSA target group patients were compared after 6 months of continuous positive airway pressure therapy.
Participants and methods: A total of 72 participants, divided into two groups, participated in the study. The control group consisted of 30 subjects, and the target group consisted of 42 subjects. In the first part of the study, the values of the audiological tests of puretone audiometry, tympanometry, auditory evoked potentials and otoacoustic emissions (TEOAE and DPOAE) and the values of the STOP-BANG questionnaire and the Epworth sleepiness scale (ESS) were compared between the target and the control group. In the second part of the study, the values of puretone audiometry, tympanometry, TEOAE, DPOAE and the results of the ESS questionnaire were compared in subjects of the target OSA group after 6 months of continuous positive airway pressure therapy.
Results: There is no significant difference in overall hearing threshold between the control and the target OSA group. The subjects of the target OSA group have a higher hearing threshold only at 1000 Hz compared to the subjects of the control group. The results in TEOAE and DPOAE showed lower SNR values in the target OSA group compared to the control group at all tested frequencies. The subjects of the target OSA group had longer latencies of the I wave and interval latencies of the I-V wave compared to the subjects of the control group, but still within the reference values. There is no significant difference in the hearing threshold for specific frequencies after six months of CPAP therapy. There is a significant difference in middle ear pressure values after CPAP therapy. There are no significant differences in TEOAE and DPOAE SNR values at any frequency after 6 months of CPAP therapy. There is no significant difference in the hearing threshold results for specific frequencies depending on the cooperation of the subjects in the treatment. After the therapy, there is a significant difference in SNR values in TEOAEs at 2 kHz and 4 kHz in subjects of the OSA target group, depending on cooperation, where they are higher in cooperative ones, while there are no significant differences at other frequencies. There is a significant difference in the SNR results in DPOAE, they are higher in cooperative ones at 1000, 6000, 7000 and 8000 Hz. The results in TEOAE after the therapy showed higher SNR values at all tested frequencies except for 2 kHz in subjects under the age of 50. The results in DPOAE after the therapy showed higher SNR values at all tested frequencies. There is no significant difference in SNR values in TEOAE and DPOAE after the therapy, depending on the presence of hypertension and type 2 diabetes.
Conclusion: In patients with obstructive sleep apnea, there is a damage of cochlear receptor cells. The use of continuous positive airway pressure as a therapy for OSA does not affect the recovery of cochlear receptor cells. The use of CPAP therapy leads to an increase in the middle ear pressure. Patients under the age of 50 have better cochlear receptor cell function after the therapy compared to those over 51. Cooperation in CPAP treatment does not affect the hearing threshold, but it does affect the function of the cochlear receptor cells, where it is better in higher frequencies in those who cooperate. The presence of comorbidities does not affect the function of the cochlear receptor cells
Development of innovative models for sustainable beach management : Doctoral thesis
No full textTurizam je važna gospodarska djelatnost u svijetu koja pridonosi ekonomskom rastu i u kojoj se zapošljava veliki broj ljudi. Plaže kao ključni prirodni resursi u turističkim destinacijama zauzimaju važnu ulogu u turističkoj ponudi. Povećanje broja dolazaka i noćenja turista u turističkim destinacijama utječe na sve veće pritiske na prirodne resurse posebice na plaže u visokoj sezonalnosti tijekom ljetnih mjeseci. Stoga se ističe potreba promišljanja i primjene novih inovativnih alata za održivo upravljanje plažama u svrhu njihove zaštite i očuvanja. Praćenje zadovoljstva turista i domicilnog stanovništva u turističkoj destinaciji je izrazito korisno s obzirom da je zadovoljstvo jedan od bitnih čimbenika koji određuje ponudu i potražnju na turističkom tržištu. Održivo upravljanje plažama je potencijalna važna tema za budući razvoj turizma u cilju održavanja i postizanja kvalitete turističke ponude na zadovoljstvo turista i domicilnog stanovništva, ali i održavanja konkurentnosti destinacije na globalnom tržištu. Upravitelji plaža se susreću s složenim izazovima kada je riječ o očuvanju plaža jer je potrebno promišljanje o planiranju i upravljanju što uključuje razvoj dugoročnih planova, uvođenje novih tehnologija i stalno praćenje učinka različitih mjera. Pregledom literature identificirani su problemi odnosno izazovi u održivom upravljanju plažama. Također su identificirani inovativni modeli koji se koriste za upravljanje plažama i to u vidu suzbijanja erozije, onečišćenja plaža te ostalih prirodnih i antropogenih utjecaja na plaže. Pregledni i empirijski dio rada može poslužiti kao polazište i podloga daljnjeg istraživanja složenog područja upravljanja plažama. Predmet istraživanja doktorske disertacije odnosi se na sustavno povezivanje relevantne teorijske i znanstvene literature u području upravljanja plažama, korištenja inovativnih alata za održivo upravljanje plažama i zadovoljstva korisnika plaža aspektima na plaži. Empirijskim istraživanjem nastoji se dokazati potencijal razvoja i implementacije modela „Zelena plaža“ za održivo upravljanje plažama na temelju percepcija i zadovoljstva korisnika plaža radi očuvanja plaža kao vrijednog prirodnog resursa. U radu su prikazani zakonodavni okvir te strateški i planski dokumenti u Republici Hrvatskoj koji se odnose na upravljanje plažama te je definiran sam pojam plaža. Detaljno je opisana glavna svrha, ciljevi, kategorije i kriterij modela „Zelena plaža“ koji potencijalno može biti ključan za učinkovito održivo upravljanje plažama. Svrha doktorske disertacije je i testirati i utvrditi postoji li utjecaj modela „Zelena plaža“ na zadovoljstvo korisnika plaža radi dokazivanja važnosti razvoja novih sličnih modela u cilju održivog upravljanja plažama. Hipoteze supostavljene polazeći od pretpostavke da model „Zelena plaža“ ima pozitivan utjecaj na zadovoljstvo korisnika plaža. Istraživanje je provedeno u ljetnim mjesecima 2018. godine nakon implementacije modela „Zelena plaža“ na plažama: Gradsko kupalište u Poreču, Karpinjan u Novigradu i Girandella u Rapcu. Istraživanjem se nastojalo utvrditi zadovoljstvo korisnika plaža aspektima na plaži, ali i utvrditi postoje li razlike prije i nakon implementacije modela „Zelena plaža“ te utječe li sam model na zadovoljstvo turista aspektima na plaži i na odabir turističke destinacije. Strukturiranim anketnim upitnikom prikupljeno je 917 odgovora korisnika plaža u 2018. godini. Disertacijom se nastoji postići znanstveni doprinos u području upravljanja plažama na održiv način, budući da je zbog sve većeg pritiska razvoja turizma nužno potrebno kretati se u smjeru korištenja inovativnih alata i modela za napredak u navedenom području. Teorijski doprinos disertacije očituje se u obogaćivanju teorijskih saznanja o održivom upravljanju plažama, predstavljanju važnosti primjene inovativnih alata za zaštitu plaža kao ključnog prirodnog resursa u turističkim destinacijama i opravdanost razvoja većeg broja modela za samoprocjenu plaža kao što je model „Zelena plaža“.
U praktičnom smislu moguća je primjena novih saznanja u vezi daljnje implementacije modela i isticanju potrebe za primjenom i stvaranjem novih modela za održivo upravljanje plažama, a sve u cilju zaštite istih. Doprinos doktorske disertacije ogleda se u testiranju i dokazivanju pozitivnog utjecaja modela „Zelena plaža“ na zadovoljstvo korisnika plaža. Budući da je dobivenim rezultatima dokazano da nezavisne varijable (sadržaji, uvjeti i prirodni uvjeti na plaži) utječu na zadovoljstvo korisnika plaža, nužno je strateški analizirati utjecaje svake od njih kako bi se kreirale preporuke za učinkovito upravljanje plažama. Istraživanjem je utvrđeno da su korisnici plaža općenito vrlo zadovoljni plažama i to ponajviše prirodnim uvjetima na plažama što govori u prilog nužnosti održivog upravljanja plažama kao visokovrijednog prirodnog resursa turističkih destinacija. Doktorski rad može poslužiti kao dobra informativna podloga za upravitelje plaža koji su zainteresirani za implementaciju modela „Zelena plaža“ u svojim destinacijama, ali i kao početno polazište za globalnu primjenu modela.Tourism is a significant economic activity that drives growth and creates numerous jobs. Beaches, as vital natural resources in tourist destinations, play a crucial role in attracting visitors. The rise in tourist arrivals and overnight stays at popular destinations puts significant pressure on natural resources, particularly on beaches during peak season.
As a result, it is crucial to consider and implement new innovative tools for the sustainable management of beaches to ensure their protection and preservation. Monitoring the satisfaction of tourists and residents in a tourist destination is extremely useful, given that satisfaction is one of the most important factors determining supply and demand in the tourist market. Effective beach management is vital for sustainable tourism, ensuring quality experiences for tourists and residents while keeping destinations competitive in the global market. Beach managers encounter significant challenges in conservation efforts. They must focus on planning and management strategies that ensure the long-term preservation of beaches.
Additionally, they need to consider implementing and testing innovative tools designed for sustainable beach management to achieve these goals. A review of the literature highlighted various problems and challenges associated with sustainable beach management. Innovative models used for beach management have also been identified as suppression of erosion, beach pollution, and other natural and anthropogenic influences on beaches. The review and empirical part of the work can be used as a starting point and basis for further research into the complex area of beach management.
The focus of the doctoral dissertation research is to systematically connect relevant theoretical and scientific literature on beach management. It explores the use of innovative tools for sustainable beach management and examines the satisfaction of beach users regarding various aspects of the beach. Empirical research aims to demonstrate the effectiveness of the "Green Beach" model for sustainable beach management, based on the perceptions and satisfaction of beach users, in order to preserve beaches as valuable natural resources. The paper presents the legislative framework and strategic and planning documents in the Republic of Croatia that relate to the management of beaches, and defines the term beach itself. The main purpose, goals, categories, and criteria of the "Green Beach" model, which can potentially be crucial for effective sustainable beach management, are described in detail. The purpose of the doctoral dissertation is to test and determine whether there is an impact of the "Green Beach" model on the satisfaction of beach users to prove the importance of developingsimilar models for sustainable beach management. The hypotheses were formulated under the assumption that the "Green Beach" model positively affects beach user satisfaction. The research was carried out in the summer months of 2018 after the implementation of the "Green beach" model on the beaches of Gradsko kupalište in Poreč, Karpinjan in Novigrad, and Girandella in Rabac. The research aimed to evaluate beach users' satisfaction with different aspects of the beach and to examine any changes before and after implementing the "Green Beach" model. It also explored how this model affects tourists' satisfaction and their choice of destination.
A structured questionnaire collected 917 responses from beach visitors in 2018. The dissertation aims to make a scientific contribution to the field of sustainable beach management. Given the increasing pressure from tourism development, it is essential to adopt innovative tools and models to advance in this area. The dissertation enhances our understanding of sustainable beach management and emphasizes the use of innovative tools for protecting essential beach resources in tourist areas. It also advocates for the development of more self-assessment models, including the "Green Beach" model. In a practical sense, it is possible to apply new knowledge regarding further implementation of the model and highlight the need for the application and creation of new models for sustainable management of beaches, all to protect them. The contribution of the doctoral dissertation is reflected in testing and proving the positive impact of the "Green Beach" model on the satisfaction of beach visitors. The results indicate that independent variables such as the content offered, the conditions of the beach, and the natural environment significantly influence the satisfaction of beach users. Therefore, it is essential to analyze the impacts of each of these factors strategically in order to develop recommendations for effective beach management. The research found that beach users are generally very satisfied with the beaches and, above all, with the natural conditions on the beaches, which speaks in favour of the necessity of sustainable beach management as a highvalue natural resource of tourist destinations. The doctoral thesis provides valuable information for beach managers interested in adopting the "Green Beach" model at their destinations and can also serve as a foundation for its global implementation
The role of mast cells in bladder cancer development in a murine model
No full textCILJEVI ISTRAŽIVANJA: Ovo istraživanje se bavilo ulogom jedne vrste imunoloških stanica, mastocita, u razvoju tumora mokraćnog mjehura. Cilj je bio bolje razumjeti kako mastociti utječu na rast tumora, te može li se blokiranjem njihove aktivnosti lijekom kromolinom utjecati na tijek bolesti. MATERIJALI I METODE: Istraživanje je provedeno na miševima uz korištenje dva različita tumorska model. U prvom modelu, miševima je dana kemikalija BBN koja s vremenom uzrokuje razvoj tumora mokraćnog mjehura. Pred kraj eksperimenta je započet tretman kromolinom kako bi se spriječila aktivacija mastocita. U drugom modelu, miševima su ispod kože ubrizgane tumorske stanice koje su s vremenom formirale tumor. U tim su eksperimentima provedena dva protokola terapije kromolinom. Terapijski protokol, u kojem je kromolin davan svakodnevno nakon što se tumor razvio, te protokol kontinuiranog tretmana, koji je započet dan prije injiciranja tumorskih stanica i provodio se do kraja eksperimenta. Kako bi se dodatno provjerilo kako mastociti utječu na razvoj tumora, oba tumorska modela su ponovljena i na miševima koji nemaju mastocite. REZULTATI: Terapijski protokol primjene kromolina (nakon pojave tumora) je rezultirao smanjenom veličinom tumora, jačom aktivacijom imunološkog odgovora i smanjenim stvaranjem novih krvnih žila za opskrbu tumora kisikom i hranjivim tvarima. S druge strane, kontinuirani protokol primjene kromolina je doveo do lošijih ishoda, odnosno većih tumora, slabijeg imunološkog odgovora i smanjenog odumiranja tumorskih stanica. Miševi bez mastocita su razvili veće tumore u potkožnim tumorskim eksperimentima, dok su u BBN eksperimentima imali nešto više invazivnih tumora. ZAKLJUČCI: Ovo istraživanje je pokazalo da mastociti imaju zaštitnu ulogu u ranoj fazi raka mokraćnog mjehura. Međutim, tijekom napredovanja bolesti mijenjaju svoje djelovanje i počinju poticati napredak tumora. Pokazano je da primjena lijeka kromolina može biti korisna ako se koristi u pravo vrijeme, no kontinuirana uporaba može imati negativne učinke.OBJECTIVES: The primary aim of this study was to explore the role of mast cells in the development and progression of bladder cancer, as well as the effects of their pharmacological inhibition using cromolyn. Particular emphasis was placed on understanding the mechanisms through which mast cells, and their inhibition, shape the tumor microenvironment. The study aimed to investigate how these factors influence gene expression, with a focus on genes involved in immune cell recruitment and activation, as well as regulation of cell death pathways. MATERIALS AND METHODS: This research utilized a murine model of bladder cancer induced by the chemical carcinogen BBN. In this model, C57BL/6J mice received intraperitoneal injections of cromolyn at a dose of 50 mg / kg every 48 hours during the final four weeks of the experiment. In addition, the study employed a subcutaneous tumor model using murine MB49 bladder cancer cells, which were injected subcutaneously into the same mouse strain. Two treatment protocols were applied in this model. In the first, therapeutic protocol, cromolyn treatment began after tumors had formed and continued daily (50 mg / kg, intraperitoneally) until the end of the experiment to evaluate its effect on tumor progression. In the second protocol, designed to mimic a scenario in which individuals are already undergoing cromolyn therapy at the time of tumor initiation, cromolyn was administered one day before MB49 cell inoculation and continued daily at the same dosage throughout the experiment. To further investigate the role of mast cells, both experimental models were also conducted using genetically mast cell-deficient mouse strains: Cpa3Cre/+ and KitW-sh/W-sh. RESULTS: In the BBN-induced model, therapeutic administration of cromolyn showed a trend toward reduced tumor mass and an improved phenotype. A similar beneficial effect was observed in the subcutaneous tumor model, where cromolyn treatment partially reduced tumor burden. Cromolyn therapy led to decreased expression of genes associated with angiogenesis and increased expression of genes involved in the activation of cytotoxic T cells and NK cells. Conversely, continuous cromolyn administration resulted in lower expression of genes essential for immune cell recruitment and activation, as well as for apoptotic and necroptotic pathways ultimately leading to a significantly increased tumor burden. Additionally, mice lacking mast cells (Cpa3Cre/+ and KitW-sh/W-sh) developed larger tumors in the subcutaneous model and showed a trend toward worse outcomes in the BBN model. CONCLUSIONS: Results of the study have shown that mast cells play a protective role in the early stages of bladder cancer but undergo phenotypic changes during tumor progression, shifting toward a protumorigenic function. Cromolyn, which primarily acts through mast cell inhibition, appears to improve the phenotype of established tumors. However, prolonged treatment was found to promote tumor progression in the mouse model
The Quality of Early and Preschool Education Institutions through Self-Assessment of the Reflective Practice of Educators, Pedagogues and Directors
No full textKvaliteta je privremen koncept različita značenja koji, kad se jednom postigne na određenoj razini, ne ostaje u trajnosti. Za pojedinca kvalitetom se smatra sve ono što se osobno unosi u „svoj svijet kvalitete”, a odnosi se na iskustva, interese, vjerovanja, vrijednosti i kulturološku određenost, dok je za organizaciju usmjerena prema zajedničkom razmišljanju i radu. Kvalitetna ustanova ranog i predškolskog odgoja i obrazovanja u ovom se istraživanju promatra kao sveobuhvatan aspekt unutar kojeg se nalaze sve kategorije rada, odnosno smatra se opširnom, univerzalnom, razvojnom i dinamičnom kategorijom. Područja kvalitete rada odnose se na misiju i viziju ustanove, vođenje, kulturu, kurikulum, odgojno-obrazovne procese, sudionike, suradnju s užom i širom zajednicom, procese praćenja i vrednovanja, kao i prostorno-materijalne, tehničke te zdravstveno-higijenske uvjete rada i sigurnost. Različitim djelovanjima djeteta, djelatnika, roditelja, lokalne zajednice i ostalih ključnih sudionika postiže se određena kvaliteta ustanove i življenja u njoj. U ovom istraživanju polazi se od pretpostavke da je refleksivna praksa odgojitelja, pedagoga i ravnatelja važan aspekt kvalitete ustanova ranog i predškolskog odgoja i obrazovanja te se smatra da je jedino zajedničkim djelovanjem moguće djelovati na istu. Uvid u samoprocjenu refleksivne prakse te povezanost sa stavovima i iskustvima o trajnom i profesionalnom razvoju, kao i procjenom međuljudskih odnosa i zadovoljstva poslom ispitanika operacionalizirao se putem kvantitativnog istraživanja. U istraživanju je sudjelovalo 814 ispitanika. Koristio se anketni upitnik koji se sastojao od 5 dijelova (Upitnik o socio-demografskim podatcima ispitanika, Upitnik o samoprocjeni refleksivne prakse, Upitnik stavova i iskustva o profesionalnom razvoju, Upitnik o procjeni suradničkih odnosa (sudionika u RPOO-u) u ustanovi te Upitnik procjene zadovoljstva poslom). U Jadranskog regiji ispitane su ukupno 72 ustanove, a u Gradu Zagrebu 30. Zbog adekvatnije raspodjele broja ispitanika po analiziranim grupama, kao i boljeg uvida u čitavu regiju koja broji sedam županija, Jadranska regija podijeljena je na dvije podregije koje uključuju Liku i Dalmaciju te Istru i Primorje, dok je Zagreb bio treća regija. Uzorak ispitanika uključuje tri grupe zanimanja u ustanovama RPOO-a. Zaključno, kao važan doprinos ovog istraživanja, pokazalo se da se svi istraživani konstrukti međusobno nadopunjuju i kreiraju ključnu ulogu u oblikovanju produktivnog, ispunjavajućeg i uspješnog radnog okruženja. Refleksivna praksa, ulaganje u profesionalni razvoj, njegovanje dobrih suradničkih odnosa i visoko zadovoljstvo poslom tvore temelj za osobnu i profesionalnu izvanrednost.Quality is a temporary concept with different meanings, which once achieved at a certain level does not remain permanent. For an individual, quality is considered to be everything that is personally brought into "one's world of quality", and refers to experiences, interests, beliefs, values and cultural determination, while for an organization it is directed towards joint thinking and work. A quality institution for early and preschool education is viewed in this research as a comprehensive aspect, within which all categories of work are located, that is, it is considered a broad, universal, developmental and dynamic category. The areas of quality of work relate to the mission and vision of the institution, management, culture, curriculum, educational processes, participants, cooperation with the narrower and wider community, monitoring and evaluation processes as well as spatial-material, technical, health-hygienic working conditions and safety. A certain quality of the institution and life in it is achieved through various actions of the child, staff, parents, local community and other key participants. This research assumes that the reflective practice of educators, pedagogues and principals is an important aspect of the quality of early childhood and preschool education institutions, and it is believed that only through joint action can it be affected. Insight into the self-assessment of reflective practice and its connection with attitudes and experiences about continuous and professional development, as well as the assessment of interpersonal relationships and job satisfaction of the respondents was operationalized through quantitative research. 814 respondents participated in the research. A questionnaire consisting of 5 parts was used (Questionnaire on socio-demographic data of the respondents, Questionnaire on self-assessment of reflective practice, Questionnaire on attitudes and experiences about professional development, Questionnaire on the assessment of collaborative relationships (participants in RPOO) in the institution, Questionnaire on the assessment of job satisfaction). A total of 72 institutions were surveyed in the Adriatic region, and 30 in the City of Zagreb. Due to a more adequate distribution of the number of respondents by analyzed groups, as well as a better insight into the entire region, which has 7 counties, the Adriatic region was divided into two sub-regions that include Lika and Dalmatia and Istria and Primorje, while Zagreb was the third region. The sample of respondents includes three occupational groups in ECEC institutions. In conclusion, as an important contribution of this study, it was shown that all the researched constructs complement each other and play a key role in shaping a productive, fulfilling and successful work environment. Reflective practice, investment in professional development, nurturing good collaborative relationships and high job satisfaction form the basis for personal and professional excellence
Evaluation of the measuring capabilities of hardness reference blocks produced by selective laser melting
No full textRazvoj etalonskih pločica tvrdoće ima ključnu ulogu u osiguravanju pouzdanosti mjerenja tvrdoće u industrijskim i istraživačkim primjenama. Selektivno lasersko taljenje (SLM) i toplinska obrada maraging čelika nude inovativni pristup u proizvodnji pločica s poboljšanom jednolikošću tvrdoće, vremenskom stabilnošću i proširenim rasponom vrijednosti tvrdoća istog polaznog materijala sa zadržavanjem zahtijevanih mjeriteljskih svojstava. Ovaj rad temelji se na detaljnoj analizi mikrostrukturnih, mehaničkih i mjeriteljskih svojstava uzoraka etalonskih pločica tvrdoće dobivenih optimiranjem postupaka proizvodnje i toplinske obrade. Provedena su mjerenja tvrdoće metodom Vickers, mikrostrukturne analize te validacija matematičkih modela s ciljem optimizacije postupka i povećanja pouzdanosti pločica kao mjeriteljskih referenci.
Teorijski dio rada obuhvaća pregled temeljnih pojmova i principa povezanih s proizvodnjom i karakterizacijom etalonskih pločica tvrdoće. Obrađene su karakteristike maraging čelika, uključujući njegov sastav, mikrostrukturu i mehanička svojstva koja ga čine pogodnim za primjenu u mjeriteljstvu. Posebna pažnja posvećena je selektivnom laserskom taljenju kao aditivnoj tehnologiji koja omogućuje proizvodnju složenih geometrija uz visoku preciznost i kontrolu mikrostrukture. Nadalje, detaljno su opisani parametri SLM-a, uključujući brzinu skeniranja, snagu lasera, debljinu sloja i razmak između prolaza, te njihov utjecaj na gustoću, poroznost i konačna svojstva materijala. Uključena je i analiza utjecaja toplinske obrade na mikrostrukturu i mehanička svojstva maraging čelika, s naglaskom na proces homogenizacijskog žarenja i starenja. Konačno, obrađeni su mjeriteljski aspekti, uključujući metode ispitivanja tvrdoće, norme HRN EN ISO 6507:2018, te statističke metode validacije i procjene mjerne nesigurnosti.
Eksperimentalni dio rada usmjeren je na razvoj etalonskih pločica tvrdoće proizvedenih selektivnim laserskim taljenjem i toplinskom obradom maraging čelika. Cilj je bio optimizirati mikrostrukturna i mjeriteljska svojstva ovih pločica kako bi postigle jednolikost tvrdoće i pouzdanost referentnih vrijednosti sa zadovoljavajućom mjernom nesigurnošću prihvatljivom za primjenu pri umjeravanju industrijskih tvrdomjera. Odabrane su kombinacije izbora metalnog praha i parametara selektivnog laserskog taljenja za postizanje maksimalne gustoće materijala pogodna za toplinsku obradu koja će osiguravati stabilnost mikrostrukture. Mikrostruktura uzoraka pločica analizirana je svjetlosnom i elektronskom mikroskopijom, dok je kemijska analiza provedena GDOES metodom. Tvrdoća pločica mjerena je Vickers metodom pri različitim opterećenjima te su rezultati korišteni za validaciju matematičkog modela koji opisuje ovisnost dobivene tvrdoće o parametrima toplinske obrade. Provedena su i interkomparacijska mjerenja s drugim laboratorijima kako bi se osigurala pouzdanost rezultata. Mjeriteljske karakteristike, od kojih je poseban naglasak na određivanju nejednolikosti površinske tvrdoće, detaljno su analizirane statističkim metodama na temelju kojih je procijenjena proširena mjerna nesigurnost izrađenih etalonskih pločica tvrdoće. Na temelju provedene analize podataka, potvrđena je visoka jednolikost i stabilnost tvrdoće etalonskih pločica dobivenih SLM postupkom i toplinskom obradom, pri čemu su postignute vrijednosti u skladu s normom HRN EN ISO 6507-3:2018. Matematički model uspješno predviđa tvrdoću u rasponu od 350 do 600 HV čime se potvrđuje pouzdanost proizvodnog postupka. Interkomparacijska mjerenja i procjena mjerne nesigurnosti pokazali su da SLM pločice zadovoljavaju mjeriteljske kriterije, otvarajući mogućnost njihove primjene u umjeravanju.The development of hardness reference blocks plays a crucial role in ensuring the reliability and accuracy of hardness measurements in both industrial and research applications. Conventional hardness reference blocks, typically made from tool steels using traditional manufacturing methods, have certain limitations regarding hardness range, homogeneity, and long-term stability. This research explores an innovative approach to producing reference blocks by utilizing Selective Laser Melting technology (SLM) in combination with heat treatment of maraging steel, aiming to improve hardness uniformity, stability, and extend the achievable range of hardness values from the same base material while maintaining the required metrological properties.
The theoretical section of this study provides an overview of the fundamental principles and methodologies related to the production and characterization of hardness reference blocks. The study emphasizes the key properties of maraging steel, including its chemical composition, microstructure, and mechanical characteristics that make it suitable for metrological applications. Special focus is given to SLM as an advanced additive manufacturing technology, which allows precise control over the microstructure, density, and porosity of the fabricated parts by adjusting critical parameters such as scanning speed, laser power, layer thickness, and hatch spacing. The impact of these parameters on the final mechanical and metrological properties is extensively reviewed. Furthermore, the research details the effects of post-processing heat treatment, particularly homogenization annealing and aging, which play a crucial role in modifying the microstructure and achieving optimum hardness values for reference applications. The study also discusses metrological aspects, including hardness measurement methods, uncertainty estimation, and compliance with the HRN EN ISO 6507-3:2018 standard.
The experimental part of this study focuses on the development, characterization, and validation of hardness reference blocks manufactured using SLM and subsequent heat treatment. The goal was to optimize microstructural and metrological properties to achieve uniform hardness distribution across the measurement surface, stable reference values suitable for long-term calibration of industrial hardness testers and acceptable measurement uncertainty, complying with international metrological standards. To achieve these objectives, a combination of metal powder selection, SLM process optimization, and controlled heat treatment parameters was used. The maraging steel powder was processed using SLM under a
range of conditions to achieve maximum material density, minimizing residual porosity while ensuring the structure remains suitable for post-processing heat treatment. The influence of these process parameters on microstructural homogeneity, grain size, and defect formation (such as porosity and oxide inclusions) was examined through optical and electron microscopy (SEM, EDX analysis). Additionally, chemical composition and phase changes due to heat treatment were analyzed using Glow Discharge Optical Emission Spectroscopy (GDOES) to ensure consistency in the final microstructure. Hardness testing was performed using the Vickers method (HV5 and HV0,5) at different loads, allowing for the evaluation of hardness uniformity and the development of a mathematical model. Statistical analysis of measurement variability was conducted, including ANOVA and F-tests, to assess whether there were significant differences in hardness distribution across different reference blocks and their respective measuring zones. The measurement uncertainty of the hardness reference blocks was determined by combining experimental data with statistical models, ensuring the results met metrological standards.
To further validate the metrological reliability of the manufactured blocks, intercomparison measurements were conducted with accredited laboratories using different hardness testing instruments, enabling an evaluation of reproducibility and consistency across independent measurements. This ensured that the reference blocks could be reliably used for calibrating industrial hardness testers, which was a key objective of the study. Preliminary one-year aging tests showed that the measured hardness values remained consistent within the estimated uncertainty, with minor variations attributed to operator-dependent measurement errors rather than actual material degradation.
The results confirmed that SLM enables precise control over microstructural properties, ensuring high-density materials with minimal porosity. Hardness uniformity and measurement reproducibility were maintained within the required uncertainty limits, confirming compliance with HRN EN ISO 6507-3:2018 standard. The developed mathematical model successfully predicted hardness values across a broad range, validating the SLM and heat treatment process for producing certified reference blocks
Contribution to the improvement of maritime navigation planning, execution and monitoring in restricted navigation areas
No full textPlaniranje pomorskog putovanja i vođenje navigacije u ograničeno plovnim područjima složen je proces čija uspješnost ovisi o mnogim čimbenicima, uključujući interakciju časnika navigacijske straže s navigacijskim informacijskim sustavima. Informacijski sustav i prikaz elektroničkih karata danas se sve više ističe kao jedino primarno navigacijsko sredstvo na zapovjednim mostovima. Međutim, ljudska pogreška i dalje je glavni uzročnik pomorskih nezgoda, dok nepravilna uporaba navigacijske opreme može dodatno povećati rizike od neželjenih događaja. Cilj ovog doktorskog rada je unaprijediti sigurnost plovidbe u ograničeno plovnim područjima kroz optimiziranu primjenu navigacijskih informacijskih sustava. Istraživanje uključuje analizu prethodnih studija i dosadašnjih istraživanja te sveobuhvatan upitnik za časnike navigacijske straže i ostale dionike plovidbenog pothvata, kako bi se stekao uvid u stavove i iskustva vezana za planiranje putovanja, vođenje navigacije, izobrazbu i rukovanje navigacijskim informacijskim sustavima te kako bi se identificirali, odnosno potvrdili utjecajni čimbenici na pojavnost postupaka i radnji čija posljedica može biti pomorska nezgoda. Metode analize ljudske pouzdanosti primijenjene su na izvještajima o pomorskim nezgodama, čime su identificirani i klasificirani ključni, raznovrsni uzroci problema vezanih za korištenje navigacijskih informacijskih sustava. Nadalje, analizirani su čimbenici koji utječu na pojavnost ljudskih pogrešaka u zadacima planiranja putovanja i vođenja navigacije u ograničeno plovnim područjima. Provedena procjena rizika navigacijskih zadataka pokazala je mogućnosti njihovog pravovremenog smanjenja. Na temelju rezultata istraživanja razvijeni su modeli planiranja putovanja i vođenja navigacije u ograničeno plovnim područjima, primjenjivi na brodovima i u nastavnim procesima. Testiranje modela provedeno je na nautičkom simulatoru, čime je potvrđena njihova učinkovitost i praktična primjenjivost. Predloženi modeli doprinose povećanju sigurnosti plovidbe i unaprjeđenju obrazovnih procesa u pomorstvu.Planning a maritime voyage and navigating in restricted waters is a complex process whose success depends on many factors, including the interaction between Officers Of the Watch (OOW) and navigation information systems. The Electronic Chart Display and Information Systems (ECDIS) increasingly becomes the primary navigation mean on the navigational bridge. However, human error remains the leading cause of maritime accidents, and improper use of navigation equipment can further increase the risks of undesirable events. The aim of this doctoral thesis is to improve the safety of navigation in restricted waters through the optimized application of navigation information systems. The research includes an analysis of previous studies and existing research, as well as a comprehensive survey for OOW’s and other stakeholders involved in the maritime voyage venture, to gain insights into their attitudes and experiences related to voyage planning, navigation, training, and handling navigation information systems, and to identify or confirm the influential factors behind procedures and actions that could lead to maritime accidents. Human reliability analysis methods were applied to maritime accident reports, identifying and classifying key and diverse causes of problems related to the use of navigation information systems. Furthermore, factors affecting the occurrence of human errors in voyage planning, execution and monitoring tasks in restricted waters were analyzed. The conducted risk assessment of navigation tasks showed opportunities for their timely reduction. Based on the research results, models for voyage planning and execution and monitoring in restricted waters were developed, which are applicable to ships and training processes. The models were tested on a nautical simulator, confirming their effectiveness and practical applicability. The proposed models contribute to increased navigational safety and the improvement of maritime educational processes
THE ROLE OF DEHYDROEPIANDROSTERONE AND ITS SULFATE, AS WELL AS BRAINDERIVED NEUROTROPHIC FACTOR IN DEMENTIA
No full textDemencija predstavlja jedan od najznačajnijih medicinskih i ekonomskih izazova današnjice.
Najčešći uzroci demencije su Alzheimerova bolest, obilježena nakupljanjem proteina Aβ i tau
u mozgu, te vaskularna demencija, izazvana ograničenim dotokom krvi u mozak. Kako trenutno
dostupne terapije samo ublažavaju simptome demencije, uz ograničenu učinkovitost i
nuspojave, istraženi su neuroprotektivni učinci dehidroepiandrosterona i njegovog sulfata
(DHEA(S)) te moždanog neurotrofnog čimbenika (BDNF). U istraživanju su korišteni stanični
(primarna kultura neurona miševa C57BL/6 i stanična linija SH-SY5Y neuroblastoma čovjeka,
izložene oligomerima Aβ, odnosno deprivaciji kisika i glukoze) i životinjski (miševi C57BL/6
injicirani s oligomerima Aβ i transgenični miševi 3xTg-AD) modeli demencija, te uzorci krvi
ispitanika s demencijom i normalnom kognicijom. Rezultati istraživanja ukazuju na blago
neuroprotektivno djelovanje DHEA(S)-a i BDNF-a u staničnim i životinjskim modelima
demencije te na smanjene razine DHEA(S)-a i povećane razine BDNF-a u plazmi ispitanika s
demencijom, upućujući na preventivni i/ili terapijski potencijal ovih supstanci, koji je potrebno
dalje istražiti.Dementia represents one of the greatest medical and economic challenges today. Most common
causes of dementia are Alzheimer’s disease, characterized by Aβ and tau accumulation in the
brain, and vascular dementia, resulting from limited cerebral blood flow. Since available
therapies only alleviate dementia symptoms, with limited efficacy and notable side effects,
neuroprotective effects of dehydroepiandrosterone and its sulfate (DHEA(S)) and brain-derived
neurotrophic factor (BDNF) were investigated. Research utilized cellular (primary neuronal
culture from C57BL/6 mice and SH-SY5Y human neuroblastoma cell line, exposed to Aβ
oligomers or oxygen and glucose deprivation), animal (C57BL/6 mice injected with Aβ
oligomers and transgenic 3xTg-AD mice) dementia models, and blood samples from dementia
and control subjects. Findings revealed mild neuroprotective actions of DHEA(S) and BDNF
in cellular and animal models of dementia, and reduced DHEAS and elevated BDNF plasma
levels in dementia patients, suggesting their preventive and/or therapeutic potential, which
should be further investigated