31. Water retention properties of stiff siltBarbara Likar, Vikica Kuk, Karmen Fifer Bizjak, 2017, izvirni znanstveni članek Povzetek: Recent research into the behaviour of soils has shown that it is in fact much more complex than can be described by the mechanics of saturated soils. Nowadays the trend of investigations has shifted towards the unsaturated state. Despite the significant progress that has been made so far, there are still a lot of unanswered questions related to the behaviour of unsaturated soils. For this reason, in the field of geotechnics some new concepts are developed, which include the study of soil suction.
Most research into soil suction has involved clayey and silty material, whereas up until recently no data have been available about measurements in very stiff preconsolidated sandy silt. Very stiff preconsolidated sandy silt is typical of the Krško Basin, where it is planned that some very important geotechnical structures will be built, so that knowledge about the behaviour of such soils at increased or decreased water content is essential.
Several different methods can be used for soil suction measurements. In the paper the results of measurements carried out on very stiff preconsolidated sandy silt in a Bishop - Wesley double-walled triaxial cell are presented and compared with the results of soil suction measurements performed by means of a potentiometer (WP4C). All the measurement results were evaluated taking into account already known results given in the literature, using the three most commonly used mathematical models. Until now a lot of papers dealing with suction measurements in normal Consolidated and preconsolidated clay have been published. Measurements on very stiff preconsolidated sandy silt, as presented in this paper were not supported before.
Ključne besede: peščeni melj, trdni melji, sukcija, Bishop - Wesley triaksialna celica, retencijska krivulja, potenciometer WP4C
Objavljeno v DiRROS: 14.08.2024; Ogledov: 220; Prenosov: 107
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32. Editorial : brain cancer pathogenesis and data integrationAndrea Comba, Xinzhong Li, Barbara Breznik, 2023, drugi znanstveni članki Povzetek: Brain tumors are one of the most aggressive malignancies in humans. They can be classified as primary tumors, which arise in the brain, or secondary tumors, which arise elsewhere in the body and initially metastaze the brain. The morbidity and mortality of brain tumors is one of the highest among cancers (Siegel et al., 2023). Of particular concern is that mortality and incidence of brain tumors are increasing, especially in the population under 44 years of age. Brain tumor mortality in this population is 13.4%. For example, primary brain tumors are the most common cancer in children and the leading cause of death in pediatric cancer patients (Gould, 2018). Considering the low survival rate of adult and pediatric brain tumor patients and the detrimental impact on patient quality of life, economic costs, and mortality rates, there is an urgent need to develop more effective therapeutic approaches. Despite major research efforts, there are currently no effective treatment modalities or prevention strategies that would significantly improve the quality of life and disease outcome of brain tumor patients.
Ključne besede: brain tumor, data integration, therapeutic resistance, biomarkers, liquid biopsies
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33. Proteases and cytokines as mediators of interactions between cancer and stromal cells in tumoursBarbara Breznik, Helena Motaln, Tamara Lah Turnšek, 2017, pregledni znanstveni članek Povzetek: Proteolytic enzymes are highly relevant in different processes of cancer progression. Their interplay with other signalling molecules such as cytokines represents important regulation of multicellular cross-talk. In this review, we discuss protease regulation mechanisms of cytokine signalling in various types of cancer. Additionally, we highlight the reverse whereby cytokines have an impact on protease expression in an autocrine and paracrine manner, representing complex feedback mechanisms among multiple members of these two protein families. The relevance of the protease-cytokine axis is illustrated in glioblastoma, where interactions between normal mesenchymal stem cells and cancer cells play an important role in this very malignant form of brain cancer.
Ključne besede: cellular cross-talk, glioblastoma, invasion, mesenchymal stem cells, protease-cytokine signalling
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34. Epithelial-to-mesenchymal transition as the driver of changing carcinoma and glioblastoma microenvironmentBernarda Majc, Tilen Sever, Miki Zarić, Barbara Breznik, Boris Turk, Tamara Lah Turnšek, 2020, pregledni znanstveni članek Povzetek: Epithelial-to-mesenchymal transition (EMT) is an essential molecular and cellular process that is part of normal embryogenesis and wound healing, and also has a ubiquitous role in various types of carcinoma and glioblastoma. EMT is activated and regulated by specific microenvironmental endogenous triggers and a complex network of signalling pathways. These mostly include epigenetic events that affect protein translation-controlling factors and proteases, altogether orchestrated by the switching on and off of oncogenes and tumour-suppressor genes in cancer cells. The hallmark of cancer-linked EMT is that the process is incomplete, as it is opposed by the reverse process of mesenchymal-to-epithelial transition, which results in a hybrid epithelial/mesenchymal phenotype that shows notable cell plasticity. This is a characteristic of cancer stem cells (CSCs), and it is of the utmost importance in their niche microenvironment, where it governs CSC migratory and invasive properties, thereby creating metastatic CSCs. These cells have high resistance to therapeutic treatments, in particular in glioblastoma.
Ključne besede: carcinomas, cancer stem cellsInvasion, proteases, tumour microenvironment
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35. Brain malignancies : glioblastoma and brain metastasesTamara Lah Turnšek, Metka Novak, Barbara Breznik, 2020, pregledni znanstveni članek Povzetek: Brain, the major organ of the central nervous system controls and processes most of body activities. Therefore, the most aggressive brain tumor – glioblastoma and metastases from other organs to the brain are lethal leaving the patients with very short time of survival. The brain tissue landscape is very different from any other tissues and the specific microenvironment, comprising stem cells niches and blood-brain barrier, significantly influences the low rate of glioblastoma metastasis out of the brain, but better accommodates brain-invading cancer. In contrast to low frequency (0.5%) of all glioblastoma metastases, 10%–45% of other primary cancers do metastasize to the brain. This review addresses general cellular and molecular pathways that are to some extent similar in both types of metastases, involving circulating tumor cells (CTCs) with cancer stem cells (CSCs) characteristics, and metastatic niches. The invasion is a dynamic process involving reversible epithelial-to-mesenchymal (EMT) cell process, creating a transient gradient state that is inter-connected with epigenetic plasticity of the metastasizing (m)CSCs. These cells can switch between stationary, low proliferating/dormant state to a migratory, mesenchymal-like state. Settling in their respective niches as dormant CSCs in the secondary organ is a common feature in all types of metastases. In glioblastoma metastasis, the malignant mGSC cells express markers of mesenchymal GSC subtype (MES-GSC), such as CD44 and YK-40 and their major obstacle seems to be propagating in the in various organs’ microenvironments, different from the niches that home GSCs in the primary glioblastoma. Focusing on one stromal component in the glioblastoma niches, the mesenchymal stem cells (MSCs), we report herein on their differential effects on glioblastoma cells, highly depending on their genetic subtype. On the other hand, in brain metastases, the major hindrance to metastatic progression of mCSCs seem to be crossing the blood-brain-barrier. Novel therapeutic approaches for brain metastases from various cancer types are advancing slowly, and the general trends involve targeting metastatic sub-clones and selective determinants of their niches. The update on the four most common brain metastases from lung, breast, melanoma and colorectal carcinoma is presented.
Ključne besede: glioblastoma, cancer stem cells, invasion, metastasis, tumor microenvironment
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36. Energy metabolism in IDH1 wild-type and IDH1-mutated glioblastoma stem cells : a novel target for therapy?Cornelis J. F. van Noorden, Vashendriya V. V. Hira, Amber J. van Dijck, Metka Novak, Barbara Breznik, Remco J. Molenaar, 2021, pregledni znanstveni članek Povzetek: Cancer is a redox disease. Low levels of reactive oxygen species (ROS) are beneficial for cells and have anti-cancer effects. ROS are produced in the mitochondria during ATP production by oxidative phosphorylation (OXPHOS). In the present review, we describe ATP production in primary brain tumors, glioblastoma, in relation to ROS production. Differentiated glioblastoma cells mainly use glycolysis for ATP production (aerobic glycolysis) without ROS production, whereas glioblastoma stem cells (GSCs) in hypoxic periarteriolar niches use OXPHOS for ATP and ROS production, which is modest because of the hypoxia and quiescence of GSCs. In a significant proportion of glioblastoma, isocitrate dehydrogenase 1 (IDH1) is mutated, causing metabolic rewiring, and all cancer cells use OXPHOS for ATP and ROS production. Systemic therapeutic inhibition of glycolysis is not an option as clinical trials have shown ineffectiveness or unwanted side effects. We argue that systemic therapeutic inhibition of OXPHOS is not an option either because the anti-cancer effects of ROS production in healthy cells is inhibited as well. Therefore, we advocate to remove GSCs out of their hypoxic niches by the inhibition of their binding to niches to enable their differentiation and thus increase their sensitivity to radiotherapy and/or chemotherapy.
Ključne besede: glioblastoma stem cells, IDH1-mutation, energy metabolism
Objavljeno v DiRROS: 05.08.2024; Ogledov: 236; Prenosov: 208
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37. Poročilo o preskusu št.: LVG 2024-081 : vzorec št. 2024/00427Nikica Ogris, Špela Hočevar, Barbara Piškur, 2024, izvedensko mnenje, arbitražna odločba Ključne besede: varstvo gozdov, morfološke analize, program preiskav, Fusarium circinatum, Pinus, borov smolasti rak, PCR
Objavljeno v DiRROS: 05.08.2024; Ogledov: 180; Prenosov: 0
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38. Poročilo o preskusu št.: LVG 2024-080 : vzorec št. 2024/00409Barbara Piškur, Špela Hočevar, 2024, izvedensko mnenje, arbitražna odločba Ključne besede: varstvo gozdov, morfološke analize, program preiskav, Fusarium circinatum, Pinus, borov smolasti rak, PCR
Objavljeno v DiRROS: 05.08.2024; Ogledov: 168; Prenosov: 0
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39. Interannual size changes of adult Aurelia sp.5 medusae stage in the Marine protected Area of Mljet Island South AdriaticTjaša Kogovšek, Juan Carlos Molinero, Davor Lučić, Ivona Onofri, Barbara Gangai, Marijana Miloslavić, Delphine Bonnet, Alenka Malej, 2012, izvirni znanstveni članek Povzetek: Aurelia aurita s.l. is the most widespread scyphozoan jellyfish that recurrently appear “en mass” and forms large aggregations mainly in coastal waters, embayments and estuaries. Beside anthropogenic factors controlling jellyfish populations climate change may play an important role. The aim of this study was to assess whether climate-related factors in absence of other anthropogenically induced stressor influence medusae size. We investigated seasonal and interannual changes in the size of Aurelia in a “jelly lake” in the National Park of Mljet Island (Croatia) where minimal human impact on the environment makes the Veliko Jezero a natural mesocosm for understanding the impact of climate change on the Aurelia population. The observed changes suggest Aurelia medusa population response to changing environment, in particular to enhanced temperature, by reduced body sizes. Comparison of Aurelia population dynamics from different regions in the Mediterranean Sea revealed the unique feature of the Veliko Jezero population. Despite the similarity of the environmental windows of medusae occurrences in the Veliko Jezero and regions in the Mediterranean Sea, medusae in the Veliko Jezero are present all year round. It seems that the lake bathymetry enables medusae to vertically migrate to deeper and cooler water layer, avoiding the limiting temperatures developed in the upper layer during the summer. These conditions may prolong the Aurelia medusae life span and together with continuous strobilation support the stability of the Aurelia medusae population all year round.
Ključne besede: Mediterraneum, moon jellyfish, Adriatic Sea, South Adriatic Sea, marine lakes, Aurelia spp, climate-related factor, Mediterranean Sea, marine research, population dynamics
Objavljeno v DiRROS: 05.08.2024; Ogledov: 187; Prenosov: 82
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40. Signatures of pigments and processes in the south Adriatic Pit - project MEDUZAMira Morović, Vesna Flander-Putrle, Davor Lučić, Branka Grbec, Barbara Gangai, Alenka Malej, Frano Matić, 2012, izvirni znanstveni članek Povzetek: During two cruises of the MEDUZA experiment conducted in July 2003 and May 2005 various data were obtained over the deepest part of the southern Adriatic Pit. Temperature, salinity, light transmission and fluorescence were measured in July 2003. During May 2005, except CTD measure- ments the samples were taken for laboratory determination of phytoplankton pigments with HPLC technique. During both cruises irradiance and radiance were measured at 14 wavelengths in the range 340-715 nm with optical probe to about 100 m depth. Bad weather conditions during both cruises caused interruption of measurements that continued after 24 to 48 hours. Stormy conditions have resulted in a slightly different structure of the water column. In the periods of measurements recorded were diurnal rhythms in a series of parameters, caused by solar radiation cycles in the surface layers as well as fluctuations in the deeper layers under the influence of the internal tide. Meteorological conditions and changes in sea level are also described. The analysis included the principal component and correlation analysis between the measured and derived parameters in order to establish a link between the in-situ pigments and multispectral data. During both cruises diurnal vertical oscillations were observed in biotic and abiotic parameters. Chlorophyll pigments prevailed over other pigments preventing other pigments to be distinguished spectrally. Regression models for chlorophyll a were established from radiance and reflectance ratios.
Ključne besede: termohaline properties, vertical migrations, Adriatic, South Adriatic Sea, diurnal rhithm, open sea, internal tide, Adriatic
Objavljeno v DiRROS: 05.08.2024; Ogledov: 322; Prenosov: 214
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