Karakterizacija šljake i pepela odloženog u Kaštel Gomilici

The objective of this study was to determine the chemical, radiological and leaching properties of slag and ash produced by a thermoelectric unit of a former factory Adriavinil and deposited in the area of Kaštel Gomilica near Split, Croatia. A total of 33 samples were analysed. The bioavailable fraction of the slag and ash was estimated using different leaching tests. The waste material was characterized by a high activity of naturally occurring radionuclides 238U, 235U and 226Ra and by elevated concentrations of heavy metals. The concentrations of most heavy metals were three to four times as high as in the common soil. Uranium slag and ash concentration was almost 40 times higher than in control soil. More than 37 % of the total U could be removed from the slag and ash with the sea water.U radu su kemijski i radiološki okarakterizirani uzorci šljake i pepela. Otpadni materijal je nastao radom termoelektričnog postrojenja bivše tvornice “Adriavinil”, a odložen je u Kaštel Gomilici u Hrvatskoj. Ukupno su analizirana 33 uzorka. Biodostupnost frakcija šljake i pepela određena je različitim testovima za izluživanje. U otpadnome materijalu određena je velika aktivnost radionuklida iz prirodnog niza, 238U, 235U i 226Ra, i povišene koncentracije teških metala. Koncentracije veæine teških metala 3 do 4 puta su veæe nego u kontrolnim uzorcima, dok je koncentracija urana veæa 40 puta. Utvrđeno je da se više od 37 % ukupnog urana iz uzorka može ukloniti izluživanjem u morskoj vodi

Strengthening of masonry walls with FRP or TRM

U novije vrijeme uz tradicionalne metode pojačanja ziđa na posmik, koriste se i noviji materijali i sustavi kao što su polimeri armirani vlaknima (FRP) i tekstilom armirani mortovi (TRM). Potres koji se dogodio u Zagrebu i okolici 22. ožujka 2020. pokazao je osjetljivost nearmiranih zidanih zgrada na horizontalna djelovanja, potrebu za sanacijom oštećenja na nosivom i nenosivom ziđu i pojačanjem ziđa na posmik. Postojeći propisi ne pokrivaju proračune pojačanja s takvim sustavima. U radu su prikazani suvremeni postupci pojačanja ziđa FRP-om ili TRM-om, znanstvena istraživanja iz tog područja, prednosti i nedostaci te proračun takvih pojačanja.In addition to traditional methods of strengthening shear masonry walls, some newer materials and systems, such as fibre reinforced polymers (FRP) and textile reinforced mortars (TRM), have recently been introduced. The earthquake that occurred in Zagreb and its surroundings on 22 March 2020 has revealed the sensitivity of unreinforced masonry buildings to horizontal actions, while pointing to the need to repair damage to load-bearing and non-load-bearing walls and to strengthen walls against shear failure. Existing regulations do not cover design of structures with such systems. The paper presents modern procedures for strengthening masonry with FRP or TRM, scientific research in this area, advantages and disadvantages, and calculation of such reinforcements

Human DLG1 and SCRIB are distinctly regulated independently of HPV-16 during the progression of oropharyngeal squamous cell carcinomas: a preliminary analysis

The major causative agents of head and neck squamous cell carcinomas (HNSCCs) are either environmental factors, such as tobacco and alcohol consumption, or infection with oncogenic human papillomaviruses (HPVs). An important aspect of HPV-induced oncogenesis is the targeting by the E6 oncoprotein of PDZ domain-containing substrates for proteasomal destruction. Tumor suppressors DLG1 and SCRIB are two of the principal PDZ domain-containing E6 targets. Both have been shown to play critical roles in the regulation of cell growth and polarity and in maintaining the structural integrity of the epithelia. We investigated how modifications in the cellular localization and protein expression of DLG1 and SCRIB in HPV16- positive and HPV-negative histologic oropharyngeal squamous cell carcinomas (OPSCC) might reflect disease progression. HPV presence was determined by p16 staining and HPV genotyping. Whilst DLG1 expression levels did not differ markedly between HPV-negative and HPV16-positive OPSCCs, it appeared to be relocated from cell–cell contacts to the cytoplasm in most samples, regardless of HPV16 positivity. This indicates that alterations in DLG1 distribution could contribute to malignant progression in OPSCCs. Interestingly, SCRIB was also relocated from cell–cell contacts to the cytoplasm in the tumor samples in comparison with normal tissue, regardless of HPV16 status, but in addition there was an obvious reduction in SCRIB expression in higher grade tumors. Strikingly, loss of SCRIB was even more pronounced in HPV16-positive OPSCCs. These alterations in SCRIB levels may contribute to transformation and loss of tissue architecture in the process of carcinogenesis and could potentially serve as markers in the development of OPSCCs

Mysterious atrial mass mimicking severe mitral stenosis

Introduction: The differential diagnosis of an intracardiac mass include benign and malignant primary heart tumors, metastatic tumors and thrombi. Primary tumors of the heart consist mainly of myxomas, with an incidence of less than 0.5%. Clinical manifestations are consequence of embolic phenomena, intracardiac obstruction or constitutional symptoms. In rare instances, myxomas can cause a mass effect, resulting in mitral valve obstruction1. Case report: 68-year-old male with a history of ulcerative colitis complained to his gastroenterologist about having exercise intolerance. Undergoing regular colitis evaluation, CT thorax and abdomen scan was performed incidentally revealing a large intracardiac mass. Echocardiogram ordered by the consulting cardiologist demonstrated a large ellipsoid left atrial cyst (50×31 mm), occupying nearly the entire left atrium (Figure 1). The mass was protruding across the mitral valve orifice in diastole causing functional stenosis with an elevated mean diastolic gradient of 10,9 mmHg. Mitral valve area calculated by pressure half-time was 1.0 cm2. Doppler showed moderate tricuspid regurgitation with a systolic pulmonary artery pressure of 50 mmHg. The systolic function was preserved with an estimated left ventricular ejection fraction of 58%. Transesophageal echocardiography described a cavitating lesion (measuring 15,1 cm2, attached to interatrial septum with 24 mm base), having characteristics consistent with a hemorrhagic cyst (Figure 2). Preoperative coronary angiography displayed coronary artery disease and a rare condition of dual coronary artery supply with left circumflex artery (LCx) providing two (Figure 3) and right coronary artery (RCA) one tumor branch (Figure 4) producing a characteric "tumor blush". CT showed large intracardiac mass (Figure 5 and Figure 6). Patient underwent cardiothoracic surgery with successful excision of the tumor (4,5x3x2 cm), the pathohistology confirmed myxoma. Postoperative course was uneventful, exercise intolerance symptoms improved, and echocardiographic follow up showed no intracardiac mass. Conclusion: We described a rare case of cystic-appearance cardiac myxoma with dual coronary supply mimicking mitral valve stenosis. There are not many patients reported with left atrial myxoma being vascularized from both RCA and LCx as seen in our case2. Although more than half of atrial myxomas show obstructive symptoms, severe mitral valve obstruction is rare1. Early echocardiographic examination of patients presenting with exertional dyspnea is advised, as myxomas have an excellent prognosis following surgical excision, preventing complications and improving quality of life

Influence of the joint modelling strategies on the response of multi-storey steel frame structure

Općenito, krutost priključaka značajno utječe na raspodjelu unutarnjih sila i momenata savijanja u konstrukcijskim elementima pa tako i na globalno ponašanje konstrukcije. Stoga, rad istražuje različite načine modeliranja priključaka i to na primjeru čelične konstrukcije višekratne zgrade. Analizirane su tri različita načina modeliranja priključaka nosač-stup. Prvi način predstavlja osno modeliranje. Najjednostavniji je te je u učestaloj primjeni u praksi. Drugi način koristi krute veze koje omogućuju uzimanje u obzir stvarne duljine stupa i nosača. Zadnji razmatrani način je Krawinklerov model. Ovaj model je najkompleksniji i najobuhvatniji jer u obzir uzima krutost priključaka kao i krutost panela hrpta stupa. Sva tri modela detaljnije su objašnjena u uvodnom teorijskom dijelu rada. Razmatran je njihov učinak na stabilnost konstrukcije, odnosno osjetljivost na učinke II. Reda kod statičke (αcr) i dinamičke analize (Θ). U radu je provedena parametarski studija na dvije osmerokatne čelične okvirne konstrukcije. Konstrukcije su prethodno dimenzionirane u skladu s europskim normama. Na temelju dobivenih rezultata doneseni su zaključci s korisnim smjernicama za buduća istraživanja.The stiffness of the joint is essential for the distribution of internal forces and bending moments in structural elements as well as global behaviour of the structure. Hence, this paper focuses on different joint modelling strategies based on the steel multistorey frame structure. Three different modelling assumptions for the beam-column joint are analysed. The first model is based on axial modelling. This is the simplest model and is often used in practice. The second model uses rigid links that allow for actual column and beam lengths to be considered. The last model considered is the Krawinkler model. It is the most complex and comprehensive because it considers the stiffness of the joint as well as the stiffness of the column web panel. All three models are explained in more detail in the theoretical part of the paper. Effect of these models on the stability of the structure, i.e. on the sensitivity to the second-order effects in case of static (αcr) and dynamic analysis (Θ) has been observed. The parametric study is performed for two 8-storey steel frame structures. In the first step structures were designed in accordance with European standards. Based on the obtained results, conclusions were drawn alongside with useful guidelines for future research

Influence of the joint modelling strategies on the response of multi-storey steel frame structure

Općenito, krutost priključaka značajno utječe na raspodjelu unutarnjih sila i momenata savijanja u konstrukcijskim elementima pa tako i na globalno ponašanje konstrukcije. Stoga, rad istražuje različite načine modeliranja priključaka i to na primjeru čelične konstrukcije višekratne zgrade. Analizirane su tri različita načina modeliranja priključaka nosač-stup. Prvi način predstavlja osno modeliranje. Najjednostavniji je te je u učestaloj primjeni u praksi. Drugi način koristi krute veze koje omogućuju uzimanje u obzir stvarne duljine stupa i nosača. Zadnji razmatrani način je Krawinklerov model. Ovaj model je najkompleksniji i najobuhvatniji jer u obzir uzima krutost priključaka kao i krutost panela hrpta stupa. Sva tri modela detaljnije su objašnjena u uvodnom teorijskom dijelu rada. Razmatran je njihov učinak na stabilnost konstrukcije, odnosno osjetljivost na učinke II. Reda kod statičke (αcr) i dinamičke analize (Θ). U radu je provedena parametarski studija na dvije osmerokatne čelične okvirne konstrukcije. Konstrukcije su prethodno dimenzionirane u skladu s europskim normama. Na temelju dobivenih rezultata doneseni su zaključci s korisnim smjernicama za buduća istraživanja.The stiffness of the joint is essential for the distribution of internal forces and bending moments in structural elements as well as global behaviour of the structure. Hence, this paper focuses on different joint modelling strategies based on the steel multistorey frame structure. Three different modelling assumptions for the beam-column joint are analysed. The first model is based on axial modelling. This is the simplest model and is often used in practice. The second model uses rigid links that allow for actual column and beam lengths to be considered. The last model considered is the Krawinkler model. It is the most complex and comprehensive because it considers the stiffness of the joint as well as the stiffness of the column web panel. All three models are explained in more detail in the theoretical part of the paper. Effect of these models on the stability of the structure, i.e. on the sensitivity to the second-order effects in case of static (αcr) and dynamic analysis (Θ) has been observed. The parametric study is performed for two 8-storey steel frame structures. In the first step structures were designed in accordance with European standards. Based on the obtained results, conclusions were drawn alongside with useful guidelines for future research

Flat-jack method for testing masonry

Nedavni seizmički događaji koji su protresli Hrvatsku naglašavaju potrebu za obnovom značajnog broja postojećih građevina. Veliki dio njih spada među ranjive nearmirane zidane konstrukcije. Kako bi obnova i pojačanje takvih konstrukcija bili efikasni i održivi, potrebno je provesti detaljne istražne radove u procesu ocjene postojećeg stanja građevinske konstrukcije korištenjem raznih metoda. Flat-jack metoda pokazala se kao vrlo korisna polurazorna metoda ispitivanja. Ona pomoću plosnatih preša unosi naprezanje u ziđe te posljedično uzrokuje njegovu deformaciju. Mjerenjem spomenutih naprezanja i deformacije te obradom dobivenih podataka osigurava se uvid u mehanička svojstva ziđa. Kroz tri faze spitivanja mogu se odrediti vertikalno stanje naprezanja, modul elastičnosti i početna posmična čvrstoća ziđa.The recent seismic events that shook Croatia made it clear that there is a great need for the renovation of a significant number of existing buildings. A large portion of these are vulnerable buildings made of unreinforced masonry. In order to make the renovation and strengthening of such structures efficient and sustainable, detailed investigations must be conducted to assess the existing condition of the structure. Various methods are used for this purpose. The flat-jack method has been proven to be a very useful semi-destructive testing method. Flat-jacks are used to apply stress to the masonry, causing it to deform. An insight into the mechanical properties of the masonry is acquired by measuring the aforementioned stresses and deformations and processing the measured data. The vertical stress state, the modulus of elasticity, and the initial shear strength of the masonry can be determined during the three test phases

Optimal treatment of patients with chronic coronary syndromes

Aktualne smjernice Europskog kardiološkog društva za stabilnu koronarnu bolest srca ističu dinamičku narav bolesti, uvode novi termin „kronični koronarni sindromi“ i razlikuju šest mogućih stanja ili scenarija. Stoga liječenje ne može kod svih bolesnika biti isto, nego treba biti prilagođeno obliku kroničnog koronarnog sindroma i individualnim osobinama svakog bolesnika. Optimalno liječenje uključuje opće nefarmakološke mjere u smislu zdravog načina života, kombinaciju odgovarajućih lijekova te razmatranje potrebe i moguću revaskularizaciju miokarda. Farmakološka terapija obuhvaća anti-ishemijske lijekove, zatim lijekove za prevenciju kardiovaskularnih događaja te optimalno liječenje glavnih čimbenika koronarnog rizika (hipertenzije, dislipidemije, šećerne bolesti). Odluka o potrebi perkutane ili kirurške revaskularizacije miokarda ovisi o prisutnosti anginoznih tegoba, ishemiji dokazanoj neinvazivnim metodama te lokalizaciji, stupnju i funkcionalnom značenju koronarnih stenoza na invazivnoj koronarografiji