Procjena pouzdanosti uređaja za mjerenje koncentracije etanola u izdahnutom zraku usporedbom s koncentracijom etanola u krvi

The main goal of this study was to determine the reliability of hand-held breath alcohol analysers currently approved for roadside screening of traffic offenders. The first part of the study included a retrospective data analysis of 714 offence records collected in 2011. Blood alcohol concentrations (BAC) obtained from the offenders 0-303 min after the police had screened them for breath alcohol concentration (BrAC) were back-calculated (cBAC) to assess the accuracy of breathalyser screening. All participants were in the alcohol elimination phase, and our analyses did not reveal any significant differences between cBAC and BrAC. To verify our findings, we performed a controlled drinking study that involved 63 healthy volunteers who consumed alcoholic beverages to simulate real drinking conditions. Immediately after alcohol consumption, BrAC was determined with a Dräger breath alcohol analyser model 6810, and 29 participants gave blood and urine sample for concomitant BAC analysis one hour later. BAC and urine alcohol concentrations were determined with headspace gas chromatography. Again, we found no significant differences between BrAC and BAC. These results confirmed the high reliability of breath alcohol analysers for measuring BrAC as long as police officers perform the measurements according to the manufacturer’s instructions.Cilj ovog istraživanja bio je utvrditi pouzdanost alkometara kojima se trenutačno koristi hrvatska policija. Prvi dio istraživanja obuhvatio je retrospektivnu analizu 714 podataka prikupljenih tijekom 2011. godine. Uzorci krvi za određivanje koncentracija etanola u krvi (BAC) prikupljeni su najkasnije 303 minute nakon mjerenja koncentracije etanola u izdahu (BrAC) te su preračunati na vrijeme mjerenja BrAC (cBAC) kako bi se procijenila preciznost alkometara. Svi sudionici bili su u fazi eliminacije etanola, a naše analize nisu otkrile statistički značajne razlike između cBAC-a i BrAC-a. Da bismo potvrdili nalaz, proveli smo drugi dio istraživanja na uzorku od 63 zdrava dobrovoljca koji su konzumirali alkoholna pića. Netom nakon konzumacije alkohola BrAC je određen Drägerovim alkometrom marke 6810, a 29 sudionika dalo je uzorak krvi i urina za istu analizu sat vremena poslije. BAC i koncentracije alkohola u mokraći određeni su plinskom kromatografijom (HS-GC-FID). Ni u ovom istraživanju nismo pronašli statistički značajnu razliku između BrAC-a i BAC-a. Ovi rezultati potvrdili su visoku pouzdanost alkometara koji mjere BrAC, pod uvjetom da policijski službenici obavljaju mjerenja prema uputama proizvođača

Razine polikloriranih bifenila u uzorcima ljudskog mlijeka u europskim zemljama

Polychlorinated biphenyls (PCBs) are persistent pollutants, harmful to human health, which enter the human body mainly through food and bind to body fat. For these reasons their use in most countries is prohibited. Human milk has an advantage over other types of human samples in measuring human exposure to PCBs, as it is obtained with non-invasive sampling methods. In Europe, including Croatia, PCB levels have been monitored for many years. This review summarises PCB trends in human milk across Europe. The trend is generally downward, with higher levels prevailing in urban areas near industrial plants. The highest PCB levels were reported in the Czech Republic and Slovakia.Poliklorirani bifenili (PCB) dobro su poznati, dugo primjenjivani spojevi koji su štetni za ljudsko zdravlje. Ljudi su im uglavnom izloženi putem hrane budući da su to spojevi koji se dugo zadržavaju u okolišu. Kad dospiju u ljudski organizam zbog lipofilnog svojstva, vežu se za masti. Danas je njihova upotreba u mnogim zemljama zabranjena. Određivanje tih spojeva u uzorcima ljudskog mlijeka ima velike prednosti s obzirom na to da je uzorkovanje mlijeka neinvazivna tehnika, a samo mlijeko, zbog lipofilnog svojstva, medij pogodan za određivanje izloženosti čovjeka PCB-ima. Najveće razine PCB-a u ljudskome mlijeku izmjerene su u urbanim područjima koja su bila u blizini industrijskih pogona. Od europskih zemalja, najveće razine PCB-a u ljudskom mlijeku pronađene su u Češkoj i Slovačkoj. U ovom radu prikazani su podaci o raspodjeli i razinama PCB-a u uzorcima majčina mlijeka u europskim zemljama u kojima se već godinama kontinuirano smanjuje njihova koncentracija

Znanje dodiplomskih studenata iz Hrvatske o temporomandibularnim poremećajima

Th e aim of this study was to evaluate Croatian undergraduate students‘ knowledge based on what they learned in the recent course, as well as the students‘ own judgment and opinions about geriatric dentistry education concerning temporomandibular disorders (TMDs) of the elderly. Th e study was carried out by means of a questionnaire administered in the last study year to students of the School of Dental Medicine, University of Zagreb and students of the Department of Dental Medicine at the School of Medicine, University of Rijeka. Th e questionnaire included questions about relevant specifi c knowledge on TMD, and statements related to their own opinion about geriatric dentistry education received during the study. Regarding students‘ knowledge related to TMDs, students from Rijeka gave more positive answers (p=0.012). Students from Rijeka gave more positive answers regarding physical therapy for treatment of TMD (p=0.004) and disc displacement and osteoarthritis as the most common disorders of the temporomandibular joint (p=0.031). Students from Zagreb were more unsatisfi ed with the skills in the fi eld of geriatric dentistry (disagreed 57.45%) than students from Rijeka (45.83% had neutral standpoint and 37.50% agreed) (p=0.005). Th e level of the participants‘ knowledge pointed to the need of improving undergraduate dental teaching about the specifi c geriatric education, including knowledge about TMD.Svrha istraživanja bila je procijeniti znanje hrvatskih dodiplomskih studenata o temporomandibularnim poremećajima (TMP) u starijih osoba, kao i njihova vlastita prosudba i mišljenje o izobrazbi iz gerontostomatologije koju uče u sadašnjim kolegijima. Istraživanje je provedeno pomoću upitnika kod studenata posljednje godine studiranja na Stomatološkom fakultetu Sveučilišta u Zagrebu i na Studiju stomatologije Medicinskog fakulteta Sveučilišta u Rijeci. Upitnik je sadržavao pitanja o važnom specifi čnom znanju o TMP, kao i stajališta vezana za vlastito mišljenje o izobrazbi iz gerontostomatologije tijekom studiranja. Vezano za znanje studenata o TMP, studenti iz Rijeke dali su više pozitivnih odgovora (p=0,012). Studenti iz Rijeke dali su više pozitivnih odgovora vezanih za fi zikalnu terapiju u liječenju TMP (p=0,004) te za pomak diska i osteoartritis kao najčešćih poremećaja čeljusnog zgloba (p=0,031). Studenti iz Zagreba bili su nezadovoljniji (nezadovoljnih 57,45%) nego studenti iz Rijeke (45,83% ih je imalo neutralno stajalište i 37,50% ih je bilo zadovoljno) vještinama iz područja gerontostomatologije (p=0,005). Razina znanja sudionika istraživanja pokazala je da je važno unaprijediti dodiplomsku nastavu stomatologije sa specifi čnom gerijatrijskom izobrazbom koja uključuje znanje o TMP

Učinci istodobne primjene THC-a i irinotekana na rast tumora i biokemijske markere na singeničnom modelu raka debelog crijeva u miševa

Clinical treatment with the antineoplastic drug irinotecan (IRI) is often hindered by side effects that significantly reduce the quality of life of treated patients. Due to the growing public support for products with Δ9-tetrahydrocannabinol (THC), even though relevant scientific literature does not provide clear evidence of their high antitumour potential, some cancer patients take unregistered preparations containing up to 80 % THC. This study was conducted on a syngeneic colorectal cancer mouse model to test the efficiency and safety of concomitant treatment with IRI and THC. Male BALB/c mice subcutaneously injected with CT26 cells were receiving 60 mg/kg of IRI intraperitoneally on day 1 and 5 of treatment and/or 7 mg/kg of THC by gavage a day for 7 days. Treatment responses were evaluated based on changes in body, brain, and liver weight, tumour growth, blood cholinesterase activity, and oxidative stress parameters. Irinotecan’s systemic toxicity was evidenced by weight loss and high oxidative stress. The important finding of this study is that combining THC with IRI diminishes IRI efficiency in inhibiting tumour growth. However, further studies, focused on more subtle molecular methods in tumour tissue and analytical analysis of IRI and THC distribution in tumour-bearing mice, are needed to prove our observations.Kliničko liječenje antineoplastičnim lijekom irinotekanom (IRI) često je otežano nuspojavama koje značajno smanjuju kvalitetu života liječenih bolesnika. Zbog sve veće javne potpore proizvodima s Δ9-tetrahidrokanabinolom (THC), iako relevantna znanstvena literatura ne daje jasne dokaze o njihovu visokom antitumorskom potencijalu, oboljeli od raka uzimaju neregistrirane pripravke koji sadržavaju i do 80 % THC-a. Ova studija provedena je na modelu singeničnoga tumora debelog crijeva u miševa kako bi se testirala učinkovitost i sigurnost istodobnog tretmana irinotekanom i THC-om. Mužjaci BALB/c miševa kojima su supkutano injicirane CT26 stanice primili su 60 mg/kg IRI-ja intraperitonealno prvi i peti dan i/ili 7 mg/kg THC-a oralno svaki dan tijekom sedam dana. Učinkovitost tretmana procijenjena je na temelju promjena u težini tijela, mozga i jetre, rasta tumora, aktivnosti kolinesteraza u krvi i parametara oksidacijskoga stresa. Sistemska toksičnost irinotekana potvrđena je smanjenjem težine miševa i povećanjem parametara oksidacijskoga stresa. Značaj je rezultata ove studije u smanjenoj učinkovitosti IRI-ja u inhibiciji rasta tumora tijekom istodobnog uzimanja s THC-om. Međutim, potrebna su daljnja istraživanja usmjerena na suptilnije molekularne metode u tumorskom tkivu i analitička analiza distribucije IRI-ja i THC-a u miševa s tumorom kako bi se dokazala naša opažanja

Citotoksično djelovanje meda obične planike (Arbutus unedo L.), ekstrakta i homogentizinske kiseline na stanične linije CAL 27, HepG2 i Caco-2

Strawberry tree (Arbutus unedo L.) honey (STH), also known as “bitter honey”, is a traditional medicine widely used in the Mediterranean area. Regardless of geographical origin, it usually has a very high content of phenolic compounds and strong antioxidant capacity. Yet, little is still known about the effects of STH, its phenolic extract (STHE), and its main bioactive compound – homogentisic acid (HGA) – at the cell level. The aim of this study was to estimate total phenolic content, DPPH radical scavenging activity, and ferric reducing antioxidant power of STH made in Croatia and investigate cytotoxic and pro-oxidative effects of STH, STHE and HGA on three human cell lines: tongue squamous cell carcinoma (CAL 27), hepatocellular carcinoma (HepG2), and epithelial colorectal adenocarcinoma cells (Caco-2) cells. These substances were tested at four concentrations (0.5–5× average human daily intake of STH) and over 30 min and 1 and 2 h. Croatian STH had a total phenolic content of 1.67 g gallic acid equivalents (GAE) per kg of honey, DPPH radical scavenging activity of 2.96 mmol Trolox equivalents (TE) per kg of honey, and ferric reducing antioxidant power (FRAP) of 13.5 mmol Fe2+ per kg of honey. Our results show no clear and consistent time- or concentration-dependent cytotoxicity in any of the cell lines. ROS levels in all the three cell types at almost all exposure times were not significantly higher than control. The most important observation is that the tested substances have low cytotoxicity and high biocompatibility, regardless of concentration, which is a good starting point for further research of their biological effects in other models.Med obične planike (Arbutus unedo L.) (STH), poznat kao “gorki med”, tradicionalno se koristi u narodnoj medicini na sredozemnom području. Bez obzira na zemljopisno podrijetlo, obično ima vrlo visok udio fenolnih spojeva i snažan antioksidacijski kapacitet. Ipak, još uvijek se malo zna o učincima STH-a, njegova ekstrakta (STHE), kao i dominantnoga fenolnog spoja – homogentizinske kiseline (HGA) – na staničnoj razini. Cilj ovoga istraživanja bio je utvrditi ukupni sadržaj fenola, antioksidacijski kapacitet metodom DPPH i FRAP u STH-u, proizvedenome u Hrvatskoj, te ispitati citotoksične i prooksidacijske učinke STH-a, STHE-a i HGA-e na tri ljudske stanične linije: karcinoma pločastih stanica jezika (CAL 27), hepatocelularnoga karcinoma jetre (HepG2) i adenokarcinoma epitela debelog crijeva (Caco-2). STH, STHE i HGA ispitani su u četirima koncentracijama (0,5–5× prosječni dnevni unos STH-a u ljudi) i tijekom 30 minuta te tijekom jednog i dva sata. Hrvatski STH imao je visok ukupan sadržaj fenola (1,67 g ekvivalenata galne kiseline po kg meda i snažan antioksidacijski kapacitet (2,96 mmol Trolox ekvivalenata po kg meda i 13,5 mmol Fe2+ po kg meda). Dobiveni rezultati ne pokazuju jasnu i dosljednu citotoksičnost, ovisno o vremenu ili koncentraciji, ni u jednoj staničnoj liniji. Razine reaktivnih kisikovih vrsta u svim trima tipovima stanica u gotovo svim vremenima izlaganja nisu bile značajno veće od kontrole. Najvažnije je zapažanje da ispitivane tvari imaju nisku citotoksičnost i visoku biokompatibilnost, bez obzira na koncentraciju, što je dobra polazna točka za daljnja istraživanja njihovih bioloških učinaka na drugim modelima

Učinak ketamina na vijabilnost, primarna oštećenja DNA i parametre oksidacijskog stresa u stanicama HepG2 i SH-SY5Y

Ketamine is a dissociative anaesthetic used to induce general anaesthesia in humans and laboratory animals. Due to its hallucinogenic and dissociative effects, it is also used as a recreational drug. Anaesthetic agents can cause toxic effects at the cellular level and affect cell survival, induce DNA damage, and cause oxidant/antioxidant imbalance. The aim of this study was to explore these possible adverse effects of ketamine on hepatocellular HepG2 and neuroblastoma SH-SY5Y cells after 24-hour exposure to a concentration range covering concentrations used in analgesia, drug abuse, and anaesthesia (0.39, 1.56, and 6.25 μmol/L, respectively). At these concentrations ketamine had relatively low toxic outcomes, as it lowered HepG2 and SH-SY5Y cell viability up to 30 %, and low, potentially repairable DNA damage. Interestingly, the levels of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione (GSH) remained unchanged in both cell lines. On the other hand, oxidative stress markers [superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT)] pointed to ketamine-induced oxidant/antioxidant imbalance.Ketamin je disocijativni anestetik koji se koristi za izazivanje opće anestezije u određenim medicinskim postupcima kod ljudi, kao i u anesteziji laboratorijskih životinja. Zbog svojih halucinogenih i disocijativnih učinaka koristi se i kao rekreacijska droga. Anestetici također mogu prouzročiti toksične učinke na staničnoj razini i, utječući na preživljavanje stanica, izazvati oštećenje DNA te neravnotežu oksidansa i antioksidansa. Cilj ove studije bio je istražiti moguće štetne učinke ketamina na hepatocelularne HepG2 i neuroblastoma SH-SY5Y stanice nakon 24-satne izloženosti širokom rasponu koncentracija, uključujući koncentracije relevantne u slučajevima korištenja u analgeziji, zlouporabi droga i anesteziji (0,39, 1,56 odnosno 6,25 μmol/L). Naši rezultati pokazali su da je ketamin u ovim ispitivanim koncentracijama izazvao relativno nisku citotoksičnost, budući da je do 30 % smanjio preživljenje stanica HepG2 i SH-SY5Y, ali je uočen neznatan porast razine primarnih oštećenja DNA. Zanimljivo je da su razine reaktivnih kisikovih vrsta (ROS), malondialdehida (MDA) i glutationa (GSH) ostale nepromijenjene u objema staničnim linijama. S druge strane, markeri oksidacijskog stresa [suporeksid dismutaza (SOD), glutation peroksidaza (GPx), katalaza (CAT)] upućivali su na oksidacijsko-redukcijsku neravnotežu izazvanu ketaminom

Preparation and characterization of 1,2-dimethylimidazolium quaternary salts (new ionic liquids)

Ionske tekućine su soli koje imaju nisko talište (<100 °C) te predstavljaju značajan potencijal za industrijsku primjenu kao “zelena“ zamjena za štetna hlapljiva organska otapala. Posebno se imidazolijeve ionske tekućine upotrebljavaju u širokom spektru zbog njihovih atraktivnih fizikalnih i kemijskih svojstava. U ovom je radu krajnji cilj bio sintetizirati nove kvaterne spojeve 1,2-dimetilimidazola. Ovi spojevi su pripravljeni reakcijom 1,2-dimetilimidazola s vodikovim peroksidom pri čemu je dobiven spoj 1,2-dimetilimidazol-N-oksid [1], koji je potom preveden u spojeve 1-butoksi-2,3-dimetilimidazolijev bromid [2] i 1-(2-hidroksietiloksi)-2,3-dimetilimidazolijev klorid [3]. Struktura novih, do sada neobjavljenih, spojeva [1]-[3] određena je pomoću podataka dobivenih IR-spektroskopijom te 1H- i 13C- nuklearno-magnetskom rezonancijom.Ionic liquids are salts with low melting point (<100 °C) having enormous potential for industrial use as “green” replacements for harmful volatile organic solvents. Especially, imidazolium ionic liquids are used in a wide variety of applications due to their attractive physical and chemical properties. In this final work, the ultimate goal was the synthesis of new quaternary salts of 1,2-dimethylimidazole. These compounds are prepared by reaction of 1,2-dimethylimidazole with hydrogen peroxide into 1,2-dimethylimidazole-N-oxide [1] which was further transformed into compounds 1- butoxy-2,3-dimethylimidazolium bromide [2] and 1-(2-hydroxyethyloxy)-2,3- dimethyilimidazolium chloride [3]. Structures of novel, yet unpublished compounds [1]-[3] were determined according to the data obtained by IR-spectroscopy as well as 1H- and 13 C-nuclear magnetic resonance

Preparation and characterization of 1,2-dimethylimidazolium quaternary salts (new ionic liquids)

Ionske tekućine su soli koje imaju nisko talište (<100 °C) te predstavljaju značajan potencijal za industrijsku primjenu kao “zelena“ zamjena za štetna hlapljiva organska otapala. Posebno se imidazolijeve ionske tekućine upotrebljavaju u širokom spektru zbog njihovih atraktivnih fizikalnih i kemijskih svojstava. U ovom je radu krajnji cilj bio sintetizirati nove kvaterne spojeve 1,2-dimetilimidazola. Ovi spojevi su pripravljeni reakcijom 1,2-dimetilimidazola s vodikovim peroksidom pri čemu je dobiven spoj 1,2-dimetilimidazol-N-oksid [1], koji je potom preveden u spojeve 1-butoksi-2,3-dimetilimidazolijev bromid [2] i 1-(2-hidroksietiloksi)-2,3-dimetilimidazolijev klorid [3]. Struktura novih, do sada neobjavljenih, spojeva [1]-[3] određena je pomoću podataka dobivenih IR-spektroskopijom te 1H- i 13C- nuklearno-magnetskom rezonancijom.Ionic liquids are salts with low melting point (<100 °C) having enormous potential for industrial use as “green” replacements for harmful volatile organic solvents. Especially, imidazolium ionic liquids are used in a wide variety of applications due to their attractive physical and chemical properties. In this final work, the ultimate goal was the synthesis of new quaternary salts of 1,2-dimethylimidazole. These compounds are prepared by reaction of 1,2-dimethylimidazole with hydrogen peroxide into 1,2-dimethylimidazole-N-oxide [1] which was further transformed into compounds 1- butoxy-2,3-dimethylimidazolium bromide [2] and 1-(2-hydroxyethyloxy)-2,3- dimethyilimidazolium chloride [3]. Structures of novel, yet unpublished compounds [1]-[3] were determined according to the data obtained by IR-spectroscopy as well as 1H- and 13 C-nuclear magnetic resonance

Preparation of biodiesel with ionic liquids

Biodizel predstavlja zamjenu za fosilna goriva koja, osim što se zalihe smanjuju, predstavljaju i opasnost za okoliš zbog stvaranja stakleničkih plinova. Danas sve više raste svijest ljudi o potrebi zaštite okoliša pa se u sintezi biodizela nastoje rabiti manje štetna otapala, djelotvorniji katalizatori te smanjiti utrošak energije. U ovom radu provedena je reakcija transesterifikacije suncokretova, repičina i sojina ulja u biodizel trima metodama: sa sintetiziranom kiselom ionskom tekućinom 3-metil-1-(4-sulfobutil)imidazolijevim hidrogensulfatom (otapalo i katalizator), s enzimom lipazom Novozyme 435 (katalizator) i sintetiziranom ionskom tekućinom 3-butil-1-metilimidazolijevim heksafluorfosfatom (otapalo) te reakcija s kiselom ionskom tekućinom 3-metil-1-(4-sulfobutil)imidazolijevim hidrogensulfatom (otapalo i katalizator) u mikrovalnom reaktoru.Biodiesel is a replacement for fossil fuels, which stocks are declining, and they represent a threat to the environment due to the production of greenhouse gases. Today, there is a growing awareness of the need to protect the environment and therefore it is important in the synthesis of biodiesel to use less harmful solvents, more efficient catalysts, and to reduce the energy consumption. In this paper, transesterification of sunflower, rapeseed and soybean oil into biodiesel was performed by three methods: with an acidic ionic liquid 3-methyl-1-(4-sulfobutyl)imidazolium hydrogensulfate (solvent and catalyst), with lipase Novozym 435 (catalyst) and acidic ionic liquid 3-butyl-1-methylimidazolium hexafluorofosfate (solvent) as well as with the acidic ionic liquid 3-methyl-1-(4-sulfobutyl)imidazolium hydrogensulfate (solvent and catalyst) in the microwave reactor

ORGANIZATION AND TRANSPORT OF CONCRETE

V diplomski nalogi bomo obravnavali problem, kako izboljšati organizacijo prevoza betona v podjetju Žiher d.o.o. Problem se nanaša na izbiro voznika za posamezno vožnjo. Izbira zahteva veliko časa, visoke stroške telefoniranja, zamude pri dostavi … Da bi izboljšali navedene procese, predlagamo prenovo organizacije prevozov betona z uvedbo sistema za nadzor in sledenje nad vozili. Sistemi sledenja zagotavljajo višjo varnost, točnost in kontrolo v transportnem procesu. Na tak način lahko pridobimo kar nekaj koristi, kot so: znižanje stroškov, varnost za voznika in vozila, povečanje izkoristka vozil in pridobivanje podatkov za potrebe analize. Za uvedbo bomo potrebovali določena finančna sredstva, čas za namestitev potrebne opreme in ustrezno usposabljanje zaposlenih.In this diploma thesis, we will analyze how to improve the organization of transport of concrete in the company Žiher d.o.o. The problem concerns the choice of driver for each drive. This choice takes a lot of time, high costs, delays in delivery … For making these processes better, we propose a modernization of the transportation organization with the system for monitoring and tracking vehicles. Modern tracking systems ensure better security, accuracy, and control in the logistic process. This way provides many advantages, such as cost reduction, safety for the driver and the vehicle, an increase in the efficiency of the vehicle and gaining information for analyzing needs. For the introduction of this, we will need certain financial means, time for installation of needed equipment, and training of the employees