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1.
SBA-15 mesoporous particles with adsorbed cresol red dye and functionalized with 3-aminopropyl groups : materials properties and dye release studies
Erika Švara Fabjan, Romana Cerc Korošec, Klara Šifrer, Andrijana Sever Škapin, Ramon Martinez Manez, 2024, original scientific article

Abstract: Research in the field of sensing has focused on tailoring the responsiveness of materials through the variation in materials properties achieved via functionalization of the mesoporous matrix. pH indicator dyes capable of protonation/deprotonation reactions are known to display different forms, resulting in changes in colour. This research focused on the preparation of mesoporous substrates SBA-15 with integrated pH indicator dye o-cresolsulphonephtalein (cresol red) grafted with (3-aminopropy) trimethoxysilane (gaining functionalized-SBA-15 material) in order to gain a colour change response following release of the dye. UV-Vis reflectance and absorbance spectra were used to evaluate forms of cresol red. The textural properties, including specific surface area, pore size distribution and pore volume were evaluated using nitrogen sorption, and XRD analysis was conducted to evaluate crystallinity of the material and pore ordering. The presence of 3-aminopropyl groups was determined by thermal decomposition using TGA–DSC/MS. The functionalized SBA-15 materials loaded with cresol red mostly retained ordering of the pores and showed a slight reduction in surface area. Functionalization changed the surface properties of the material. In the non-functionalized SBA-15, cresol red was present in both double (H2L) and single (HL−) protonated forms, whereas in the functionalized SBA-15 the deprotonated L2−form prevailed. Through desorption experiments cresol red was successfully desorbed from selected sample to different media. The change of colour caused by alterations in the form of the dye once released from the mesoporous silica material into the medium was confirmed. The form of cresol red released was determined by the pH of the medium.
Keywords: mezoporozni materiali, SBA-15, funkcionalizacija, uravnavanje odzivnosti, zaznavanje
Published in DiRROS: 13.02.2024; Views: 113; Downloads: 59
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Quality control of thermally modified timber using dynamic vapor sorption (DVS) analysis
Miha Humar, Rožle Repič, Davor Kržišnik, Boštjan Lesar, Romana Cerc Korošec, Christian Brischke, Lukas Emmerich, Gregor Rep, 2020, original scientific article

Abstract: The importance of thermal modification is increasing worldwide. Increased use of thermally modified timber (TMT) has resulted in a need for reliable quality control, comprising control of variation of the production within defined limits, allowing third-party control in the case of certification and the regulation of customer complaints and claims. Techniques are thus needed to characterise the modification of quality in terms of improved target properties of TMT during industrial production, and of TMT products that have been in service for an arbitrary time. In this study, we aimed to utilise dynamic vapor sorption (DVS) for this purpose. Norway spruce (Picea abies) and European beech (Fagus sylvatica) samples were thermally modified at different temperatures according to different heat treatment techniques: (1) the Silvapro process based on an initial vacuum; (2) an air heat treatment, whereby samples were wrapped in aluminium foil; (3) thermal modification of wood samples in the ambient atmosphere in a laboratory oven. Wood samples from closed processes were analysed for validation. TMT was characterised with respect to mass loss, colour and density. Mass loss of wood due to modification (MLTM) was correlated with factors derived from DVS analysis. The present DVS measurements suggest that the equilibrium wood moisture content (EMC95% RH), the time to reach 10% wood moisture content (t10% MC), and the elongation factor, c, derived from a logarithmic function, can serve as alternative parameters to characterise the quality of several thermal modification processes. Further studies are recommended using other wood species, different modification processes and further parameters gained from DVS measurements to understand the robustness and the predictive power of the applied technique
Keywords: thermal modification, quality control, dynamic vapour sorption, wood, moisture content
Published in DiRROS: 31.08.2023; Views: 258; Downloads: 133
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4.
Metal and non-metal modified titania : the effect of phase composition and surface area on photocatalytic activity
Boštjan Žener, Lev Matoh, Martin Reli, Andrijana Sever Škapin, Romana Cerc Korošec, 2022, original scientific article

Abstract: The application of TiO 2 photocatalysis in various environmental fields has been extensively studied in the last decades due to its ability to induce the degradation of adsorbed organic pollutants. In the present work, TiO 2 powders doped and co-doped with sulfur and nitrogen and modified with platinum were prepared by particulate sol-gel synthesis. PXRD measurements revealed that the replacement of HCl with H 2SO4 during synthesis reduced the size of the crystallites from ~ 30 nm to ~20 nm, increasing the surface area from ~44 m2/g to ~80 m2/g. This is consistent with the photocatalytic activity of the samples and the measured photocurrent behavior of the photocatalysts. The results showed that the prop- erties of the powders (i.e., surface area, crystallite size, photocurrent behavior) depend strongly not only on the type but also on the amount of acid and dopants used in the synthesis. Doping, co-doping and modification of TiO 2 samples with nitrogen, sulfur and platinum increased their photocatalytic activity up to 6 times.
Keywords: titanium dioxide, powders, doping, photocatalysis, photocurrent, SEM
Published in DiRROS: 04.05.2023; Views: 284; Downloads: 122
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5.
Improved synthetic route of incorporation of nanosilicon species into phenol-formaldehyde resin and preparation of novel ZnAl-layered double-hydroxide hybrid phenol-formaldehyde resin
Ana Dremelj, Romana Cerc Korošec, Andreja Pondelak, Branka Mušič, 2022, original scientific article

Abstract: Hybrid phenol-formaldehyde (PF) resins represent one of the most important niche groups of binding systems for composites. New industrial needs, environmental requirements, and price fluctuations have led to further research on materials with enhanced mechanical and thermal properties. The preparation of novel hybrid materials can be achieved by inclusion of various elements or functional groups in the organic polymer phenolic framework. Herein, we report the synthesis and characterization of a PF-based hybrid material with different nanoscale silicone species and ZnAl-layered double hydroxide (LDH). The main goals of this study were to improve the synthetic pathways of hybrid resin, as well as to prepare granulated composite materials and test samples and determine their characterization. Added inorganic species increased the glass-transition temperature by a minimum of 8 °C, which was determined using differential scanning calorimetry (DSC). Rheological properties (melting viscosity and flow distance) of the hybrid resin were measured. The homogeneity of distribution of added species across the organic matrix was evaluated with scanning electron microscopy (SEM). With synthesized new hybrid-binding systems, we prepared different granulated composite materials and evaluated them with the measurements of rheological properties (flow curing characteristics). Tensile strength of samples, prepared from granulated composite material, improved by more than 5%.
Keywords: phenol-formaldehyde hybrid resins, nano-SiO2, ZnAl-LDH, composites, glass-transition temperature, mechanical properties
Published in DiRROS: 03.05.2023; Views: 347; Downloads: 152
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6.
Priporočila za zobozdravstveno obravnavo odraslih bolnikov z rakom glave in vratu v Sloveniji, zdravljenih z obsevanjem
Aleš Fidler, Aleksandar Aničin, Vojislav Didanovič, Tadej Dovšak, Boris Gašpirc, Aleš Grošelj, Andrej Kansky, Matic Koren, Jana Krapež, Hojka Kuralt, Marko Kuralt, Boštjan Lanišnik, Romana Mance Kristan, Jošt Pavčič, Luka Prodnik, Peter Pukl, Tadej Ostrc, Milan Kuhar, Eva Skalerič, Robert Šifrer, Valerija Skopec, Primož Strojan, 2022, original scientific article

Abstract: Priporočila za zobozdravstveno obravnavo bolnikov z rakom glave in vratu (RGV) v Sloveniji, zdravljenih z obsevanjem sledijo priporočilom The Royal College of Surgeons of England v sodelovanju z The British Society for Disability and Oral Health, dopolnjujejo Priporočila za obravnavo bolnikov z rakom glave in vratu v Sloveniji in hkrati upoštevajo obstoječe zmožnosti slovenskega zdravstvenega sistema. Namen priporočil je prepre-čevanje oz. zmanjšanje zapletov v ustni votlini, ki nastanejo zaradi obsevanja. Opredeljujejo način zobozdravstvene oskrbe pred, med in po zdravljenju raka na vseh treh nivojih zobozdra-vstvene oskrbe, kar zagotavlja njeno pravočasnost in dostopnost. Priporočila predstavljajo poenoteno mnenje vseh deležnikov na področju zobozdravstvene obravnave bolnikov z RGV v državi.
Keywords: onkologija, zobozdravstvena obravnava, obsevanje, ustna votlina, priporočila
Published in DiRROS: 14.07.2022; Views: 556; Downloads: 189
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7.
In-depth rheological characterization of tungsten sol-gel inks for inkjet printing
Urša Opara Krašovec, Tjaša Vidmar, Marta Klanjšek Gunde, Romana Cerc Korošec, Lidija Slemenik Perše, 2022, original scientific article

Keywords: rheology, inkjet printing, tungsten oxide, sol-gel
Published in DiRROS: 11.02.2022; Views: 730; Downloads: 508
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8.
Heterogeneous response of airway eosinophilia to anti-IL-5 biologics in severe asthma patients
Maruša Kopač, Matija Rijavec, Peter Korošec, Urška Bidovec, Izidor Kern, Romana Vantur, Sabina Škrgat, 2022, original scientific article

Abstract: Many questions concerning responders (R) and nonresponders (NR) in severe eosinophilic asthma (SEA) after blocking the IL-5 (interleukin 5) pathway are still not clear, especially regarding the early parameters of response to biologics in personalized treatment strategies. We evaluated 17 SEA patients treated with anti-IL-5 biologics (16 patients mepolizumab, one patient benralizumab) before the introduction of biologics, and at a week 16 follow-up. Clinical, cellular and immunological parameters in peripheral blood were measured in R and NR. Sputum induction with the measurement of cellular and immunological parameters was performed at 16 weeks only. There were 12 R and 5 NR to biologics. After 16 weeks, there was a significant improvement in percentages of FEV1 (p = 0.001), and asthma control test (ACT) (p = 0.001) in the R group, but not in NR. After 16 weeks, the eosinophils in induced sputum were 27.0% in NR and 4.5% in R (p = 0.05), with no difference in IL-5 concentrations (p = 0.743). Peripheral eosinophilia decreased significantly in NR (p = 0.032) and R (p = 0.002). In patients with SEA on anti-IL-5 therapy, there was a marked difference in airway eosinophilic inflammation between R and NR already at 16 weeks, after anti-IL-5 introduction.
Published in DiRROS: 13.01.2022; Views: 934; Downloads: 535
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9.
Chemokines during anaphylaxis : the importance of CCL2 and CCL2-dependent chemotactic activity for basophils
Romana Vantur, Maruša Rihar, Ana Koren, Matija Rijavec, Peter Kopač, Urška Bidovec, Renato Eržen, Peter Korošec, 2020, original scientific article

Abstract: Background: The role of chemokines in anaphylaxis is unclear. Methods: We prospectively recruited 49 patients presenting to the emergency department with an acute episode of anaphylaxis and 28 healthy subjects. We measured serum levels of the chemokines CCL2, CCL5, CCL7, CCL8, CCL11, CCL13, CCL17, CCL21, CCL22, CCL24, and CCL26, tryptase, the absolute number of circulating basophils, monocytes, lymphocytes, and PMNs, and whole blood FCER1A, CPA3 and HDC gene expression at two time points: during the anaphylactic episode and in convalescent samples collected approximately 3 months later. We then investigated the in vitro chemotactic activity of chemokines induced during anaphylaxis for the in vitro migration of the corresponding cells. Results: Only CCL2 chemokine levels were signifcantly increased in anaphylaxis samples (median 514 pg/ml) compared to convalescent samples (284 pg/ml, P<0.0001) and healthy subjects (279 pg/ml, P<0.0001); there was no signifcant diference in any of the other chemokines. There was a signifcant positive correlation between the rates of increase of serum CCL2 (median [range]: 106.0% [-44.7% to 557.4%]) and tryptase (133.8% [-6.6% to 893.4%]; r=0.68, P<0.0001) and between the acute concentration of serum CCL2 and the acute concentration of serum tryptase (r=0.77, P<0.0001). The number of circulating basophils, but not other blood cells, signifcantly decreased during anaphylaxis (median 5.0 vs. 19.1 cells/[micro]l in convalescent samples; P<0.0001); a decrease in whole-blood gene expression of basophil markers (PKeywords: anaphylaxis, chemokines, tryptases, basophils, chemotaxis, CCL2, cell migration
Published in DiRROS: 18.01.2021; Views: 1299; Downloads: 612
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10.
Individualna obravnava bolnika in bližnjih v posvetovalnici onkološke zdravstvene nege
Vesna Jašič, Romana Krivec Matijašič, 2019, published professional conference contribution

Keywords: zdravstvena nega, onkološko zdravljenje, bolniki, individualna obravnava
Published in DiRROS: 21.01.2020; Views: 1851; Downloads: 550
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