1. An experimental study of liquid micro-jets produced with a gas dynamic virtual nozzle under the influence of an electric fieldBor Zupan, Gisel Esperanza Peña-Murillo, Rizwan Zahoor, Jurij Gregorc, Božidar Šarler, Juraj Knoška, Alfonso M. Gañán-Calvo, Henry N. Chapman, Saša Bajt, 2023, original scientific article Abstract: The results of an experimental study of micro-jets produced with a gas dynamic virtual nozzle (GDVN) under the influence of an electric field are provided and discussed for the first time. The experimental study is performed with a 50% volume mixture of water and ethanol, and nitrogen focusing gas. The liquid sample and gas Reynolds numbers range from 0.09–5.4 and 0–190, respectively. The external electrode was positioned 400–500 μm downstream of the nozzle tip and an effect of electric potential between the electrode and the sample liquid from 0–7 kV was investigated. The jetting parametric space is examined as a function of operating gas and liquid flow rates, outlet chamber pressure, and an external electric field. The experimentally observed jet diameter, length and velocity ranged from 1–25 μm, 50–500 μm and 0.5–10 m/s, respectively. The jetting shape snapshots were processed automatically using purposely developed computer vision software. The velocity of the jet was calculated from the measured jet diameter and the sample flow rate. It is found that micro-jets accelerate in the direction of the applied electric field in the downstream direction at a constant acceleration as opposed to the standard GDVNs. New jetting modes were observed, where either the focusing gas or the electric forces dominate, encouraging further theoretical and numerical studies towards optimized system design. The study shows the potential to unlock a new generation of low background sample delivery for serial diffraction measurements of weakly scattering objects. Keywords: micro jet, electric field, experimental study, flow focusing, Taylor cone, gas dynamic virtual nozzles Published in DiRROS: 07.02.2024; Views: 135; Downloads: 54 Full text (1,94 MB) This document has many files! More... |
2. Modificirajući uticaj na neke endokrine žlezde miša kod kasnih posledica subletalnog jonizacionog zračenjaMiroslav Kališnik, Olga Vraspir-Porenta, Metka Logonder-Mlinšek, Marjeta Zorc, Tatjana Lejko-Zupanc, Alenka Rus-Gaši, Draga Štiblar-Martinčič, Janez Škrk, 1979, original scientific article Published in DiRROS: 14.09.2023; Views: 242; Downloads: 55 Full text (558,37 KB) |
3. Composite landslide in the dynamic alpine conditions: a case study of Urbas landslideEla Šegina, Mateja Jemec Auflič, Matija Zupan, Jernej Jež, Tina Peternel, 2022, original scientific article Abstract: The alpine environment is characterized by complex geology, high-energy terrain, deeply incised river valleys with high erosional potential, extreme weather conditions and dynamic geomorphic processes. Such settings provide favourable conditions for the formation of composite landslides rather than individual slope mass movement phenomena. As an example, we present the kinematics of the composite landslide Urbas in the North of Slovenia which developed in the complex geological and morphological settings characteristic of the alpine environment. The research combines several monitoring techniques and involves the integration of both surface and subsurface displacements measured in the landslide area. The results indicate that the composite sliding process consists of several simultaneous and interrelated types of movements occurring in different segments of the unstable mass that are governed by different mechanisms of displacements, such as rockfall, sliding and debris flow. The kinematic characteristics of a deep-seated landslide that formed in such conditions vary spatially, but is rather homogenuous vertically, indicating translational type of movement. Spatial kinematic heterogeneity is primarily related to the diverse terrain topography, reflecting in different displacement trends. Based on the revealed kinematic proprieties of the sliding material, the sediment discharge illustrates the sliding material balance which estimates the volume of the retaining material that represents the potential for slope mass movement events of larger scales. Keywords: composite landslide, alpine conditions, kinematics, monitoring, sediment discharge Published in DiRROS: 15.12.2022; Views: 582; Downloads: 164 Full text (8,00 MB) |
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5. Minimalno invazivni diagnostični pristopi pri primarnih možganskih tumorjih z uporabo prosto cirkulirajočih nukleinskih kislinMarija Skoblar Vidmar, Jernej Mlakar, Uroš Smrdel, Alenka Matjašič, Jože Pižem, Andrej Zupan, 2021, published scientific conference contribution Keywords: tekočinska biopsija, onkološko zdravljenje, možganski tumorji Published in DiRROS: 04.04.2022; Views: 568; Downloads: 219 Full text (123,97 KB) |
6. Robust saliva-based RNA extraction-free one-step nucleic acid amplification test for mass SARS-CoV-2 monitoringEva Rajh, Tina Šket, Arne Praznik, Petra Sušjan, Alenka Šmid, Dunja Urbančič, Irena Mlinarič-Raščan, Polona Kogovšek, Tina Demšar, Mojca Milavec, Katarina Prosenc, Žiga Jensterle, Mihaela Zidarn, Viktorija Tomič, Gabriele Turel, Tatjana Lejko-Zupanc, Roman Jerala, Mojca Benčina, 2021, original scientific article Abstract: Early diagnosis with rapid detection of the virus plays a key role in preventing the spread of infection and in treating patients effectively. In order to address the need for a straightforward detection of SARS-CoV-2 infection and assessment of viral spread, we developed rapid, sensitive, extraction-free one-step reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and reverse transcription loop-mediated isothermal amplification (RT-LAMP) tests for detecting SARS-CoV-2 in saliva. We analyzed over 700 matched pairs of saliva and nasopharyngeal swab (NSB) specimens from asymptomatic and symptomatic individuals. Saliva, as either an oral cavity swab or passive drool, was collected in an RNA stabilization buffer. The stabilized saliva specimens were heat-treated and directly analyzed without RNA extraction. The diagnostic sensitivity of saliva-based RT-qPCR was at least 95% in individuals with subclinical infection and outperformed RT-LAMP, which had at least 70% sensitivity when compared to NSBs analyzed with a clinical RT-qPCR test. The diagnostic sensitivity for passive drool saliva was higher than that of oral cavity swab specimens (95% and 87%, respectively). A rapid, sensitive one-step extraction-free RT-qPCR test for detecting SARS-CoV-2 in passive drool saliva is operationally simple and can be easily implemented using existing testing sites, thus allowing high-throughput, rapid, and repeated testing of large populations. Furthermore, saliva testing is adequate to detect individuals in an asymptomatic screening program and can help improve voluntary screening compliance for those individuals averse to various forms of nasal collections. Keywords: SARS-CoV-2, COVID-19, COVID-19 serological testing, real-time polymerase chain reaction, saliva, oral cavity swab, passive drool, pooling Published in DiRROS: 09.11.2021; Views: 1047; Downloads: 534 Link to full text |
7. Platformne storitveAna Robnik, Andrej Ciglič, Aleš Balanč, Dušan Gabrijelčič, Jan Porekar, Arso Savanović, Polona Škraba, Roman Kužnar, Ignac Zupan, 2015, published scientific conference contribution Published in DiRROS: 08.12.2020; Views: 1271; Downloads: 383 Full text (608,68 KB) |
8. Prevalence of and factors associated with healthcare-associated infections in Slovenian acute care hospitals : results of the third national surveyIrena Klavs, Mojca Serdt, Aleš Korošec, Tatjana Lejko-Zupanc, Blaž Pečavar, 2019, original scientific article Abstract: Introduction. In the third Slovenian national healthcare-associated infections (HAIs) prevalence survey, conducted within the European point prevalence survey of HAIs and antimicrobial use in acute care hospitals, we estimated the prevalence of all types of HAIs and identified factors associated with them. Methods. Patients were enrolled into a one-day cross-sectional study in November 2017. Descriptive analyses were performed to describe the characteristics of patients, their exposure to invasive procedures and the prevalence of different types of HAIs. Univariate and multivariate analyses of association of having at least one HAI with possible risk factors were performed to identify risk factors. Results. Among 5,743 patients, 4.4% had at least one HAI and an additional 2.2% were still treated for HAIs on the day of the survey, with a prevalence of HAIs of 6.6%. The prevalence of pneumoniae was the highest (1.8%), followed by surgical site infections (1.5%) and urinary tract infections (1.2%). Prevalence of blood stream infections was 0.3%. In intensive care units (ICUs), the prevalence of patients with at least one HAI was 30.6%. Factors associated with HAIs included central vascular catheter (adjusted odds ratio [aOR] 4.1; 95% confidence intervals [CI]: 3.1–5.4), peripheral vascular catheter (aOR 3.0; 95% CI: 2.3–3.9), urinary catheter (aOR 1.8; 95% CI: 1.4–2.3). Conclusions. The prevalence of HAIs in Slovenian acute care hospitals in 2017 was substantial, especially in ICUs. HAIs prevention and control is an important public health priority. National surveillance of HAIs in ICUs should be developed to support evidence-based prevention and control. Keywords: healthcare-associated infections, prevalence, survey, risk factors, Slovenia Published in DiRROS: 16.10.2020; Views: 2282; Downloads: 858 Full text (255,15 KB) This document has many files! More... |
9. The impact of scald development on phenylpropanoid metabolism based on phenol content, enzyme activity, and gene expression analysisAnka Čebulj, Heidrun Halbwirth, Maja Mikulič Petkovšek, Robert Veberič, Ana Slatnar, 2020, original scientific article Keywords: scald, gene expression, hydroxycinnamic acids, color, enzyme activity, phenol content, scald development, apples, cold storage Published in DiRROS: 03.09.2020; Views: 1677; Downloads: 522 Full text (907,32 KB) |
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