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Query: "author" (Drago A%C5%BEman) .

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1.
Middle Triassic deeper-marine volcano-sedimentary successions in western Slovenia
Dragomir Skaberne, Jože Čar, Maja Pristavec, Boštjan Rožič, Luka Gale, 2024, original scientific article

Abstract: A Ladinian – Carnian volcano-sedimentary succession from western Slovenia, paleogeographically belonging to the western Slovenian Basin, is presented in 17 sections. Except for the lowermost part, which is dominated by volcanics and volcaniclastics, most of the succession is dominated by shale, sandstone, and micritic limestone. Various authors use the name Pseudozilja and/or Amphiclina formation for this part, which is dominated by clastics, but they disagree on the differences between the formations. The lower Pseudozilja formation, represented by the Malenski Vrh section, comprises diabase, tuf and shale. No substantial differences in lithological composition have been observed between the upper Pseudoziljaformation and the Amphiclina formation, which are predominantly composed of shale, sandstone, and limestone. The shale and sandstone are largely composed of quartz, feldspar, and lithic grains (especially volcanics), which vary in proportions. Limestone varieties comprise hemipelagic limestones and resedimented carbonates deposited by gravity-flows. Deposition of the Ladinian – Carnian volcano-sedimentary succession took place on or near the continental slope that was generally inclined to the S, with the direction of transport mainly from N to S.
Keywords: stratigraphy, carbonate-siliciclastic deposits, Slovenian Basin, Middle Triassic, Ladinian, Carnian, Pseudozilja formation, Amphiclina formation
Published in DiRROS: 09.07.2024; Views: 186; Downloads: 89
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2.
Petrology dataset of Pliocene-Pleistocene sediments in northeastern Slovenia
Eva Mencin Gale, Polona Kralj, Mirka Trajanova, Luka Gale, Dragomir Skaberne, 2024, other scientific articles

Abstract: This is a dataset of petrological analysis of Pliocene-Pleistocene f luvial sediments from 14 gravely samples from the Slovenj Gradec, Nazarje, Celje and Drava-Ptuj Basin (northeastern Slovenia), collected for clast lithological analysis. The petrological analysis includes description of 155 thin sections of metamorphic, volcanic, volcaniclastic, clastic and carbonate rocks. This dataset provides grounds for determining the provenance of these gravel deposits, revealing possible resedimentation processes, and serves as a tool for drainage network interpretation in the Pliocene-Pleistocene.
Keywords: petrografska analiza, litološka analiza klastov, provenienca klastov, pliocensko-pleistocenski sedimenti
Published in DiRROS: 09.07.2024; Views: 223; Downloads: 104
.pdf Full text (2,92 MB)

3.
Indoor navigation with a Smartphone
Drago Torkar, 2024, independent scientific component part or a chapter in a monograph

Abstract: This chapter presents a cost-effective system for indoor localization and navigation that does not require the use of satellite positioning or data communication networks. The system, implemented as a smartphone app, relies on QR codes that are pre-generated and attached to the walls inside the building. By utilizing the information from these codes and the smartphone’s inertial motion unit (IMU) sensors processed by the Pedestrian Dead-Reckoning (PDR) algorithm, the user’s current position can be determined. The Dijkstra navigation algorithm is then used to guide the user to the desired destination. The smartphone app can also be used as a healthcare logistics service in mass-casualty incidents for collecting and reporting georeferenced triage decisions to the cloud.
Keywords: internet thinks, indoor navigation, systems, QR codes
Published in DiRROS: 02.07.2024; Views: 218; Downloads: 122
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4.
Explainable anomaly detection of 12-Lead ECG signals using denoising autoencoder
Rok Hribar, Drago Torkar, 2024, independent scientific component part or a chapter in a monograph

Abstract: The basic idea was to create a proof of concept demonstrating that the indoor navigation and localisation is possible using only passive tags. For this purpose, a smartphone navigation app was developed to be used in inner parts of the buildings and which can operate with no satellite positioning service available and no communication network present. The satellite navigation systems (GPS, GLONASS, Galileo, BeiDou, QZSS, IRNSS) inside buildings, at least on lower floors and cellars, in central parts, and away from windows, usually do not work, or their accuracy is very reduced due to a small number of visible satellites. The communication networks (WiFi, LTE, 5G…) might not be available in some circumstances such as catastrophic incidents, power reductions, or similar, which disables the localisation systems based on them. The purpose of the smartphone app was twofold. First, to develop a reliable, simple-to-use, and cheap indoor navigation system that could be used in large buildings like hospitals, shopping malls, trade centres, fairs, etc. where no other positioning service is available. Second, to develop an indoor position reporting system that can be used in accidents and mass-casualty incidents for reporting triage decisions to the server. Both functionalities are based on the QR codes [1] holding all the information needed.
Keywords: internet thinks, indoor navigation, systems, QR codes
Published in DiRROS: 02.07.2024; Views: 201; Downloads: 145
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5.
Characterization of micro-threaded stem taper surface of cementless hip endoprostheses
Drago Dolinar, Boštjan Kocjančič, Klemen Avsec, Barbara Šetina, Aleksandra Kocijan, Matjaž Godec, Marko Sedlaček, Mojca Debeljak, John T. Grant, Timon Zupanc, Monika Jenko, 2024, original scientific article

Abstract: We investigated micro-threaded stem taper surface and its impact on premature failures, aseptic loosening, and infection in cementless hip endoprostheses. Our study focused on the fretting, and crevice corrosion of micro-threaded tapers, as well as the characterization of the microstructure and surface properties of two new and three retrieved Zweymüller stem tapers. The retrieved samples were selected and examined based on the head–stem taper interface being the sole source of modularity with a metallic component, specifically between the Ti alloy taper stem and the ceramic head. To determine the surface chemistry and microstructures of both new and retrieved hip endoprostheses stem taper titanium alloy, scanning -electron microscopy (SEM) was employed for morphological and microstructural analyses. Energy dispersive spectroscopy (EDS) was utilized for characterizing chemical element distribution, and electron backscattered diffraction (EBSD) was used for phase analysis. The roughness of the micro-threated stem tapers from different manufacturers was investigated using an optical profilometer, with standard roughness parameters Ra (average surface roughness) and Rz (mean peak to valley height of the roughness profile) being measured. Electrochemical studies revealed no fretting corrosion in retrieved stem tapers with ceramic heads. Consequently, three retrieved tapers and two new ones for comparison underwent potentiodynamic measurements in Hank’s solution to determine the corrosion rate of new and retrieved stem taper surfaces. The results showed a low corrosion rate for both new and prematurely failed retrieved samples due to aseptic loosening. However, the corrosion rate was higher in infected and low-grade infected tapers. In conclusion, our study suggests that using ceramic heads reduces taper corrosion and subsequently decreases the incidence of premature failures in total hip arthroplasty.
Keywords: total hip arthroplasty, stem micro-threaded taper, taper surface morphology, microstructure, corrosion, Ti implant alloy
Published in DiRROS: 06.06.2024; Views: 281; Downloads: 242
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6.
Long-term survival in glioblastoma : methyl guanine methyl transferase (MGMT) promoter methylation as independent favourable prognostic factor
Uroš Smrdel, Mara Popović, Matjaž Zwitter, Emanuela Boštjančič, Andrej Zupan, Viljem Kovač, Damjan Glavač, Drago Bokal, Janja Jerebic, 2016, original scientific article

Abstract: In spite of significant improvement after multi-modality treatment, prognosis of most patients with glioblastoma remains poor. Standard clinical prognostic factors (age, gender, extent of surgery and performance status) do not clearly predict long-term survival. The aim of this case-control study was to evaluate immuno-histochemical and genetic characteristics of the tumour as additional prognostic factors in glioblastoma. Long-term survivor group were 40 patients with glioblastoma with survival longer than 30 months. Control group were 40 patients with shorter survival and matched to the long-term survivor group according to the clinical prognostic factors. All patients underwent multimodality treatment with surgery, postoperative conformal radiotherapy and temozolomide during and after radiotherapy. Biopsy samples were tested for the methylation of MGMT promoter (with methylation specific polymerase chain reaction), IDH1 (with immunohistochemistry), IDH2, CDKN2A and CDKN2B (with multiplex ligation-dependent probe amplification), and 1p and 19q mutations (with fluorescent in situ hybridization). Methylation of MGMT promoter was found in 95% and in 36% in the long-term survivor and control groups, respectively (p < 0.001). IDH1 R132H mutated patients had a non-significant lower risk of dying from glioblastoma (p= 0.437), in comparison to patients without this mutation. Other mutations were rare, with no significant difference between the two groups. Molecular and genetic testing offers additional prognostic and predictive information for patients with glioblastoma. The most important finding of our analysis is that in the absence of MGMT promoter methylation, longterm survival is very rare. For patients without this mutation, alternative treatments should be explored.
Keywords: glioblastoma, long-term survival, methyl guanine methyl transferase, MGMT, prognostic factor
Published in DiRROS: 30.04.2024; Views: 335; Downloads: 316
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7.
Mechanisms of premature fracture in modular neck stems made of CoCrMo/Ti6Al4V and Ti6Al4V/Ti6Al4V alloy
Drago Dolinar, Miro Gorenšek, Klemen Avsec, Barbara Šetina, Matej Hočevar, Matjaž Godec, Borut Žužek, Mojca Debeljak, Monika Jenko, John T. Grant, Boštjan Kocjančič, 2023, original scientific article

Abstract: In this paper, we present the mechanisms of premature fracture of modular neck stems in two case studies: (I) when the neck and stem are both made of the same Ti6Al4V alloy, and (II) when the neck and stem are made from two different alloys, CoCrMo and Ti6Al4V alloy. Our study integrates two orthopedic patients who have undergone primary uncemented THA for usual indications in two orthopedic centers (Community Health Centre and University Medical Centre). Both centers are part of the national public health care system. Both surgeries were performed by two skilled orthopedic surgeons with more than 10 years of experience in THA. The survivorship of the modular neck of cast CoCrMo alloy was 24 months. The survivorship of the modular neck from Ti6Al4V alloy was 84 months. Multivariate analyses were performed to assess the differences in the fretting, corrosion, and fatigue of the two prematurely failed modular neck stems: stereo light microscopy (SLM), scanning electron microscopy (SEM), X-ray energy-dispersive spectroscopy (EDS), and electron backscatter diffraction (EBSD). Patient demographic information, including sex, age, body mass index, survivorship of implants, and reason for the revision, was collected from medical records. We found that fretting and fatigue occurred on both neck-stem retrievals due to additional galvanic corrosion, but the CoCrMo/Ti6Al4V alloy system suffered more corrosion due to additional galvanic corrosion and fractured earlier than the Ti6Al4V/Ti6Al4V metal alloy system. Both metallic alloy systems used in this application are known to be highly corrosion-resistant, but the bio-tribo-corrosion processes need to be understood in detail and characterized so that appropriate improvements in design and materials can be made.
Keywords: total hip arthroplasty, modular neck, Ti6Al4V alloy, CoCrMo alloy, corrosion
Published in DiRROS: 07.02.2024; Views: 536; Downloads: 284
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