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72. Solid carriers of potentially toxic elements and their fate in stream sediments in the area affected by iron ore mining and processingSaša Kos, Nina Zupančič, Mateja Gosar, Miloš Miler, 2022, original scientific article Abstract: The potential environmental impact of historical mining and ore processing on stream sediments and water was studied in a small siderite iron ore deposit with diverse sulfide mineral paragenesis. The main aim was to characterize solid carriers of potentially toxic elements (PTEs) in stream sediments and mine waste, to understand their fate in fluvial systems. General mineralogy (X-ray powder diffraction) and individual solid PTE carriers (scanning electron microscopy/energy dispersive spectroscopy) were correlated with the geochemical composition of stream sediments, mine waste, and stream waters (inductively coupled plasma mass spectrometry). Primary solid PTE carriers were pyrite, chalcopyrite, sphalerite, Hg-bearing sphalerite, galena, and siderite. Slightly alkaline and oxidizing conditions in stream water promoted the transformation of primary phases into secondary PTE carriers. Fe(Mn)-oxide/oxyhydroxides were major sinks for Pb, Zn, and As. Compared to background levels, Co (14.6 ± 2.1 mg/kg), Cu (30 ± 2.9 mg/kg), Ni (32.1 ± 2.9 mg/kg), Pb (64.5 ± 16.4 mg/kg), Zn (175.3 ± 22.5 mg/kg), As (81.1 ± 63.7 mg/kg), and Hg (2 ± 0.8 mg/kg) were elevated in mining area. Mine waste contained similar PTE carriers as stream sediments, but much higher PTE contents. Prevailingly low PTE concentrations in streams, with the exception of As (1.97 ± 2.4 µg/L) and Zn (4.5 ± 5.7 µg/L), indicate the stability of PTE carriers. Environmental effects were not significant, and additional monitoring is recommended.
Keywords: environmental mineralogy, environmental geochemistry, potentially toxic elements, stream sediments, solid phases, iron ore deposit, SEM/EDS
Published in DiRROS: 16.11.2022; Views: 547; Downloads: 176
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75. Priporočila za obravnavo bolnic z rakom jajčnikov, jajcevodov in s primarnim peritonealnim seroznim rakom v SlovenijiNina Kovačević, 2022, not set Keywords: serozni rak, diagnostika, sledenje pacientov, recidiv, epidemiologija, histopatologija, kirurško zdravljenje, sistemsko zdravljenje, radioterapija, gensko svetovanje, zdravstvena obravnava, smernice, zborniki
Published in DiRROS: 10.11.2022; Views: 591; Downloads: 153
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76. 3. šola o sarkomih : Mezenhimski tumorji maternice2022, not set Keywords: rak (medicina), multidisciplinarna obravnava, klasifikacija, diagnostika, patološka histologija, kirurško zdavljenje, biološko zdravljenje, sistemsko zdravljenje, radioterapija, sledenje pacientov, zborniki
Published in DiRROS: 09.11.2022; Views: 610; Downloads: 257
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77. Effects of desiccation and freezing on microbial ionizing radiation survivability : considerations for Mars sample returnWilliam H. Horne, Tine Grebenc, Rok Tkavc, Cene Gostinčar, Nina Gunde-Cimerman, 2022, original scientific article Abstract: Increasingly, national space agencies are expanding their goals to include Mars exploration with sample return. To better protect Earth and its biosphere from potential extraterrestrial sources of contamination, as set forth in the Outer Space Treaty of 1967, international efforts to develop planetary protection measures strive to understand the danger of cross-contamination processes in Mars sample return missions. We aim to better understand the impact of the martian surface on microbial dormancy and survivability. Radiation resistance of microbes is a key parameter in considering survivability of microbes over geologic times on the frigid, arid surface of Mars that is bombarded by solar and galactic cosmic radiation. We tested the influence of desiccation and freezing on the ionizing radiation survival of six model microorganisms: vegetative cells of two bacteria (Deinococcus radiodurans, Escherichia coli) and a strain of budding yeast (Saccharomyces cerevisiae); and vegetative cells and endospores of three Bacillus bacteria (B. subtilis, B. megaterium, B. thuringiensis). Desiccation and freezing greatly increased radiation survival of vegetative polyploid microorganisms when applied separately, and when combined, desiccation and freezing increased radiation survival even more so. Thus, the radiation survival threshold of polyploid D. radiodurans cells can be extended from the already high value of 25 kGy in liquid culture to an astonishing 140 kGy when the cells are both desiccated and frozen. However, such synergistic radioprotective effects of desiccation and freezing were not observed in monogenomic or digenomic Bacillus cells and endospores, which are generally sterilized by 12 kGy. This difference is associated with a critical requirement for survivability under radiation, that is, repair of genome damage caused by radiation. Deinococcus radiodurans and S. cerevisiae accumulate similarly high levels of the Mn antioxidants that are required for extreme radiation resistance, as do endospores, though they greatly exceed spores in radioresistance because they contain multiple identical genome copies, which in D. radiodurans are joined by persistent Holliday junctions. We estimate ionizing radiation survival limits of polyploid DNA-based life-forms to be hundreds of millions of years of background radiation while buried in the martian subsurface. Our findings imply that forward contamination of Mars will essentially be permanent, and backward contamination is a possibility if life ever existed on Mars.
Keywords: ionizing radiation, life on Mars, astrobiology, radiation, fungi, bacteria, radiotolerance
Published in DiRROS: 03.11.2022; Views: 602; Downloads: 290
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78. Treatment outcomes and relative dose intensity of chemotherapy in patients with advanced Hodgkin lymphomaSamo Rožman, Barbara Jezeršek Novaković, Nina Ružić Gorenjec, Srdjan Novaković, 2022, original scientific article Abstract: The present retrospective study was undertaken to investigate the association of relative dose intensity (RDI) with the outcome of patients with advanced stage Hodgkin lymphoma (HL) receiving ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine) and escalated BEACOPP regimens (bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, prednisone). A total of 114 patients with HL treated between 2004 and 2013 were enrolled for evaluation. The association of variables with overall survival (OS) and progression-free survival (PFS) was analysed using univariate and multivariate Cox proportional hazards models. The median age of patients was 39 years, and the majority were male and had stage IV disease. A total of 54 patients received ABVD and 60 received BEACOPP chemotherapy with 24 and four deaths, respectively. Patients in the BEACOPP group were significantly younger with lower Charlson comorbidity index (CCI) and better performance status in comparison with the ABVD group, making the comparison of groups not possible. In the ABVD group, RDI was not significantly associated with OS (P=0.590) or PFS (P=0.354) in a multivariate model where age was controlled. The low number of events prevented this analysis in the BEACOPP group. The age of patients was strongly associated with both OS and PFS; all statistically significant predictors for OS and PFS from univariate analyses (chemotherapy regimen, CCI, RDI, performance status) lost their effect in multivariate analyses where age was controlled. Based on these observations, it was concluded that RDI was not associated with OS or PFS after age is controlled, neither in all patients combined nor in the ABVD group.
Keywords: Hodgkin lymphoma, chemotherapy, outcome, primary treatment
Published in DiRROS: 23.09.2022; Views: 551; Downloads: 165
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80. Contrast-enhanced ultrasound for evaluation of tumor perfusion and outcome following treatment in a murine melanoma modelMaja Brložnik, Nina Boc, Maja Čemažar, Maša Omerzel, Monika Savarin, Nataša Kejžar, Gregor Serša, Darja Pavlin, Simona Kranjc Brezar, 2021, original scientific article Published in DiRROS: 23.09.2022; Views: 505; Downloads: 305
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