Kakovost v visokem šolstvu je relativna in funkcionalna. Razpeta je med različne interese in hkrati vse manj zavezana univerzi lastnemu jeziku, logiki in vrednotam. Empirična raziskava evalvacijskih ...praks v Sloveniji prikazuje občutljivost kakovosti za razlike med stopnjami in vrstami študijskih programov ter disciplinami, v katere so študijski programi vpeti. Intrinzična raznoličnost študija je izpeljana tako iz pristopov v visokošolskem izobraževanju, specialnih didaktik in razlik med disciplinami kot iz razlik, ki jih opredeljujejo področni predpisi. Rezultati raziskave na podlagi analize vrednostnih sodb o kakovosti v končnih evalvacijskih poročilih strokovnjakov v postopkih podaljšanja akreditacije študijskih programov sporočajo, da kritičnost in pogostost kvalitativnih poudarkov strokovnjakov slabo sledita nujnostim intrinzičnih posebnosti vrst in stopenj študijskih programov, še posebej pa njihove vpetosti v različne discipline. Ker tudi področna primernost skupin strokovnjakov pri tem skorajda ne nadoknadi neobčutljivosti področnih predpisov za intrinzične posebnosti študija, kakovost ogroža svojevrstnost praks in procesov v visokem šolstvu.
Ferroptosis: regulated cell death Čepelak, Ivana; Dodig, Slavica; Dodig, Daniela Čepelak
Arhiv za higijenu rada i toksikologiju,
06/2020, Letnik:
71, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Ferroptosis is a recently identified form of regulated cell death that differs from other known forms of cell death morphologically, biochemically, and genetically. The main properties of ferroptosis ...are free redox-active iron and consequent iron-dependent peroxidation of polyunsaturated fatty acids in cell membrane phospholipids, which results in the accumulation of lipid-based reactive oxygen species due to loss of glutathione peroxidase 4 activity. Ferroptosis has increasingly been associated with neurodegenerative diseases, carcinogenesis, stroke, intracerebral haemorrhage, traumatic brain injury, and ischemia-reperfusion injury. It has also shown a significant therapeutic potential in the treatment of cancer and other diseases. This review summarises current knowledge about and the mechanisms that regulate ferroptosis.
Urbanisation and industrialisation are on the rise all over the world. Environmental contaminants such as potentially toxic elements (PTEs) are directly linked with both phenomena. Two PTEs that ...raise greatest concern are arsenic (As) and lead (Pb) as soil and drinking water contaminants, whether they are naturally occurring or the consequence of human activities. Both elements are potential carcinogens. This paper reviews the mechanisms by which As and Pb impair metabolic processes and cause genetic damage in humans. Despite efforts to ban or limit their use, due to high persistence both continue to pose a risk to human health, which justifies the need for further toxicological research.
The floristic investigation of the Ionian island of Kalamos resulted in the addition of 275 specific and infraspecific taxa, which are reported here, to a present total of 502 taxa. For each newly ...recorded taxon local distribution and habitat types are presented. Convolvulus pentapetaloides and Malcolmia graeca subsp. hydraea are reported for the first time from the Ionian islands. Some of the new records concern rare taxa in Greece or regional endemics, which are, therefore, chorologically significant, such as Alkanna corcyrensis, Stachys ionica, Heptaptera colladonioides. A brief description of some of the vegetation types of the island is given. The results of floristic analysis and phytogeographical aspects demonstrate the pronounced Mediterranean character of the island’s flora.
Na otoku Kalamos smo s floristično raziskavo odkrili 275 novih taksonov na nivoju vrste in nižje ob do sedaj že poznanih 502 taksonih. Za vsak novo odkrit takson predstavljamo lokalno razširjenost in habitatni tip. Taksona Convolvulus pentapetaloides in Malcolmia graeca subsp. hydraea smo na ionskih otokih našli prvič. Nekatere nove najdbe so redki taksoni ali lokalni endemiti, kot so Alkanna corcyrensis, Stachys ionica, Heptaptera colladonioides in so horološko pomembni. Podali smo tudi kratek opis nekaterih vegetacijskih tipov otoka. Rezultati floristične analize in fitogeografskih vidikov kažejo izrazito mediteranski značaj preučevanega rastlinstva.
The hot-deformation behavior of A356 aluminum alloy with a Sr modification was investigated using a Gleeble 1500 thermal simulator. The true stress-strain curves with a deformation temperature of ...300–500 °C and a strain rate of 0.01–5 s–1 were clarified. The activation energy of the A356 aluminum alloy with Sr modification was 221.474 kJ/mol. The influences of friction and temperature on the curves were investigated, and then the constitutive equation was established. The results show that the flow stress is obviously affected by temperature and strain rate. The experimental stress is lower than the theoretical stress, and the stress difference between the experimental and theoretical stress increases with the increasing strain. The maximum stress difference reaches 17.8 MPa when the sample deformed at 300 °C/5 s–1 with a reduction of 16 %. For all the deformation conditions the correlation coefficient is 0.99 and the average relative error is 4.8 %, which shows the good predictability of the current model. The developed constitutive equation can provide guidance for the study of the hot-deformation behavior of similar aluminum alloys.
Production of free radicals and oxidative damage during physical activity is a topic that is intensively studied and paid a lot of attention, first of all in professional sports. Marathon is ...categorized as extremely demanding sports discipline, as it induces high energy consumption and also requires special mental self-control. We presented cases of two athletes of different age, who have been on dissimilar level of sports readiness, and also had various approach to physical activity and exercise. During 10 days they ran out 10 marathons, partly on a flat terrain, and partly on hilly, which produced different level of effort in conquering the terrain. Also, both athletes had complex supplementation scheme in order to prevent electrolyte imbalance and excessive production of free radicals. Blood samples were taken in the morning and immediately after the end of the marathon. Measured oxidative stress biomarkers changed without a noticeable pattern, but these changes did not vary greatly among themselves. Catalase activity in both marathon runners was higher after marathon almost after every race for 10 days. On the other hand, amount of reduced glutathione was lower after marathon in both athletes in the same manner. Based on the obtained results we can conclude that adequate supplementation could have crucial role in prevention of oxidative damage.
Strawberry tree (
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 Fe
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.
Veličina i svojstva sjemenki jagodastih voćnih vrsta važan su parametar koji utječe na iskoristivost sjemenki odnosno produkciju pojedinih kemijskih komponenti prilikom njihova iskorištavanja kao ...nusprodukta prerade plodova. Sjemenke manjih dimenzija potrebno je opisivati s što više parametara, a danas je to moguće računalno razvijenim metodama. Cilj rada bio je utvrditi masu, opisati i analizirati sjemenke jagodastih voćnih vrsta (jagoda, malina, kupina, ribiz, borovnica, ogrozd i josta) pomoću WinSEEDLE™ sustava, a na temelju morfometrijskih svojstava utvrditi razlike između pojedinih vrsta. Nakon provedenih istraživanja može se zaključiti da se jagodaste voćne vrste značajno razlikuju u izgledu kao i morfometrijskim svojstvima sjemenki. Najveća masa stotinu sjemenki utvrđena je kod bijelog ribiza, a najmanja kod šumske jagode i borovnice. Najveća projicirana površina te ravna duljina i ravna širina sjemenki utvrđena je kod bijelog ribiza, nešto manje vrijednosti utvrđene su kod kupine, a najmanje kod jagode. Analiza sjemenki pomoću novijih sofisticiranih metoda predstavlja značajan izvor podataka za dopunu istraživanja u vrednovanju vrsta i sorata. S obzirom da pojedine jagodaste voćne vrste sadrže dosta velik broj sjemenki koje uglavnom ostaju neiskorištene ili najčešće predstavljaju nusproizvod čak i otpad prilikom prerade plodova, rezultati ovakvih istraživanja mogu olakšati odabir pojedine vrste za određenu namjenu.
Uređenje gradskih zelenih površina u Hrvatskoj karakterizira primjena egzotičnih ukrasnih vrsta dok je upotreba hrvatskih samoniklih vrsta sporadična i oslanja se na manji broj dobro poznatih vrsta. ...Istraživanja pokazuju da Europljani pozitivno percipiraju egzotične vrste te ih smatraju atraktivnijim i zanimljivijim od samoniklih vrsta. Neke zemlje su siromašne samoniklom florom te je stoga razumljivo njihovo oslanjanje na alohtone vrste. Nasuprot tomu, hrvatska flora je bogata samoniklim vrstama te kao takva predstavlja nepresušan izvor za introdukciju novih vrsta u uzgoj i primjenu. Osim slabe osviještenosti šire javnosti, ali i profesionalaca, o važnosti upotrebe samoniklih vrsta u uređenju gradskih zelenih površina, velik problem predstavlja i njihova dostupnost. Trenutno se ponuda hrvatskih rasadnika bazira uglavnom na stranim ukrasnim vrstama. Slabo ulaganje u znanstvena istraživanja čiji bi cilj bio uvođenje novih vrsta u uzgoj i upotrebu je dodatan problem. U cilju procjene potencijala hrvatske bresine (Micromeria croatica) za uvođenje u uzgoj, sakupljeni su osnovni podaci o ovoj samonikloj, endemskoj vrsti Dinarida. U radu je dat pregled njene rasprostranjenosti, morfoloških značajki, ekologije i moguće primjene.
Landscaping of urban green spaces in Croatia is characterized by the use of exotic plant species while the use of Croatian native plants is sporadic and relies on small number of well-known species. Studies show that Europeans perceive positively exotic species and find them more attractive and interesting than native plants. Some countries are characterized by species-poor flora and it is therefore understandable that they rely on non-native species. However, Croatian flora is rich in native species and in that way represents inexhaustible source for introduction of new species into cultivation and landscape use. Apart from low public and professional awareness of the significance of using native plants in landscaping urban green areas, a major problem represents the availability of native plants. Currently, Croatian nurseries offer mostly non-native ornamentals. Poor investment in scientific research aiming at introduction of new species into cultivation and use is another problem. In order to evaluate potential of Micromeria croatica for introduction into cultivation, basic data on this endemic species of the Dinarides mountain range were gathered. In the paper its distribution, morphological traits, ecology and possible landscape use are discussed.
Cilj ovog istraživanja bio je utvrditi kemijski sastav i hranjivu vrijednost dominantnih vrsta i podvrsta travnjačke zajednice Scorzoneretalia villosae. Istraživanje je provedeno na travnjacima ...visoravni Ćićarije. U sakupljenim uzorcima 17 dominantnih biljaka određen je sadržaj suhe tvari (ST) i u njoj sadržaj sirovog proteina (SP), organske tvari, neutralnih detergent vlakana (NDV), kiselih detergent vlakana (KDV), kiseli detergent lignin (KDL), in vitro probavljivost suhe tvari (IVPST) te neto energija (NEL). Prema proljetnom sadržaju SP i IVPST, najhranjivije za ovce i vrlo palatabilne su bile Hippocrepis comosa (SP 181 g/kg ST; IVPST 63,5%), Scorzonera villosa (SP 121 g/kg ST; IVPST 61,5%) i Satureja montana ssp. variegata (SP 83 g/kg ST; IVPST 60,4%), a najnepovoljniji kemijski sastav imale su Stipa pennata ssp. eriocaulis (NDV 790; KDV 396; ADL 112 g/kg ST) i Brachypodium pinnatum ssp. rupestre (NDV 789; KDV 483; ADL 86 g/kg ST). Utvrđena je visoka IVPST vrste Salvia pratensis (maks. 70,6%) i generalno hepatotoksične vrste Teucrium chamaedrys (67,1%) koja za lokalno stado ovaca nije toksična. Pokazatelji hranjivosti istraživanih vrsta i podvrsta prvi su put prikazani u ovom radu.
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