41. Vehicle–bridge interaction modelling using precise 3D road surface analysisMaja Kreslin, Peter Češarek, Aleš Žnidarič, Darko Kokot, Jan Kalin, Rok Vezočnik, 2024, izvirni znanstveni članek Povzetek: Uneven road surfaces are the primary source of excitation in the dynamic interaction between a bridge and a vehicle and can lead to errors in bridge weigh-in-motion (B-WIM) systems. In order to correctly reproduce this interaction in a numerical model of a bridge, it is essential to know the magnitude and location of the various roadway irregularities. This paper presents a methodology for measuring the 3D road surface using static terrestrial laser scanning and a numerical model for simulating vehicle passage over a bridge with a measured road surface. This model allows the evaluation of strain responses in the time domain at any bridge location considering different parameters such as vehicle type, lateral position and speed, road surface unevenness, bridge type, etc. Since the time domain strains are crucial for B-WIM algorithms, the proposed approach facilitates the analysis of the different factors affecting the B-WIM results. The first validation of the proposed methodology was carried out on a real bridge, where extensive measurements were performed using different sensors, including measurements of the road surface, the response of the bridge when crossed by a test vehicle and the dynamic properties of the bridge and vehicle. The comparison between the simulated and measured bridge response marks a promising step towards investigating the influence of unevenness on the results of B-WIM.
Ključne besede: interakcija vozilo in most, terestično lasersko skeniranje, neravnost vozišča, numerično modeliranje
Objavljeno v DiRROS: 26.01.2024; Ogledov: 213; Prenosov: 86
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42. Can we rely on cancer mortality data? Checking the validity of cervical cancer mortality data for SloveniaMaja Primic-Žakelj, Vera Pompe-Kirn, Fani Škrlec, Jožica Šelb-Šemerl, 2001, izvirni znanstveni članek Povzetek: Background. Valid inference on cervical cancer mortality is very difficult since - on the basis of death certificates - it is not always possible to distinguish between cervix, corpus and unspecified uterine cancer deaths. Our aim was to estimate the extent to which cervical cancer as the official cause of death reflects the true mortality from cervical cancer in Slovenia. Material and methods. The data on 2245 deaths from cervix, corpus uteri, and uterus-unspecified cancers for the period 1985-1999 were linked to the Cancer Registry of Slovenia database from the mortality database of Slovenia. Results. Officially, in the period 1985-1999, there were 878 cervical cancer deaths. The comparison of these causes of death with the cancer sites registered in the Cancer Registry revealed that they include only 87.7 % patients with a previous diagnosis of cervical cancer. Of 650 corpus uteri cancer deaths, 17.1% of patients were registered to have cervical cancer, and of 717 unspecified uterine cancer deaths, 31.4% were registered. Taking into account the correctly identified cervical cancer cases among cervical cancer deaths and misclassified cervical cancer deaths as corpus uteri and unspecified uterine, the corrected number of deaths would be 1106. Conclusions. When evaluating the impact of cervical cancer mortality from national mortality rates, the stated underestimation should be taken into account. However, this does not hold for some other cancers.
Objavljeno v DiRROS: 26.01.2024; Ogledov: 126; Prenosov: 36
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43. MRI macromolecular contrast agents as indicators of changed tumor blood flowTeodora Ivanuša, Katarina Beravs, Maja Čemažar, Vladimir Jevtič, Franci Demšar, Gregor Serša, 2001, izvirni znanstveni članek Povzetek: Background. A rapid mapping technique derived from dynamic contrast enhanced MRI data was used to identify and characterize reduction of blood flow in fibrosarcoma SA-1 tumors treated either by application of electric pulses or vinblastine. Materials and methods. Tissue permeability surface area product (PS) and fractional blood volume (BV) were calculated on a pixel-by-pixel basis using dynamic MRI intensity data after administration of gadomer - 17 orpolylysine-Gd-DTPA; prototypic macromolecular contrast agents designed for blood pool enhancement. PS and BV values of untreated tumors were compared to those of tumors treated by local application of 8 electric pulses (amplitude/distance ratio, 1300 V/cm; duration, 100 us, frequency, 1 Hz) percutaneously to the tumor or by systemic administration of vinblastine (2.5 mg/kg). Results. Both treatments transiently, but significantly reduced tumor blood flow, application of electric pulses to the tumors being by 40% more effective in reducing tumor blood flow than systemic administration of vinblastine. PS and BV values derived with polylysine-Gd-DTPA-enhanced MRI were lower compared to those with gadomer-17, due to larger molecular size. Interestingly, Gd-DTPA-enhanced MRI did not show any significant changes of PSand BV between untreated and treated tumors. Conclusion. This study demonstrates that dynamic contrast enhanced MRI can be effectively used to qualitatively monitor tumor blood flow, and quantitatively by means of BV and PS.
Objavljeno v DiRROS: 25.01.2024; Ogledov: 156; Prenosov: 35
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44. Computer systems for determination od pressure distribution in the hip joint articular surface : validation and resultsVlado Stankovski, Dragica Smrke, 2001, izvirni znanstveni članek Povzetek: Background. In this work, we describe the computer systems Viprecox and ActiveContours that are used in the process of realistic estimation of some biomechanical parameters of the hip joint, including the maximal value of the stress in the hip joint p max. The computer system Active Contours uses standard anteroposterior radiographs of the whole pelvis and both hips for itscalculations and Viprecox in its kernel uses a relatively simple three-dimensional mathematical model of stress distribution in the hip-joint articular surface which has been extensively elsewhere (e.g. Iglič 1996). Material and methods. Both state-of-the-art computer systems were tested by analysing the calculated values of p max for 81 patients (37 males and 44 females). Conclusions. In this way we prove that the described computer systems can be used for the determination of the contact stress distribution from standard AP radiographs.
Objavljeno v DiRROS: 25.01.2024; Ogledov: 154; Prenosov: 29
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45. Antitumor effectiveness of bleomycin on SA-1 tumor after pretreatment with vinblastineMaja Čemažar, Marija Auersperg, Gregor Serša, 2000, izvirni znanstveni članek Povzetek: In our previous study, vinblastine (VLB) was shown to increase the plasma membrane fluidity. This effect of VLB might be exploited for better transport of drugs through the plasma membrane. The aim of the present study was to determine whether pretreatment with VLB can increase the cytotoxic effect of BLM on intraperitoneal SA-1 tumors in mice. Materials and methods. BLM and VLBwere used as single agents or in various combinations, i.e. BLM injected 24h before VLB or vice-versa, VLB injected 24 h before BLM. Cell and animal survival together with DNA histograms were the end-points used to determine the effect of these combined treatments. Results. Both drugs, either as singletreatment or in different combined therapy schedules reduced significantly the number of cells in peritoneal lavage, compared to control, saline treated animals. The combination of VLB, followed by BLM after 24 h reduced significantly the number of cells in peritoneal lavage, compared to the treatment in which BLM was followed by VLB or to the treatment with singledrugs alone. Median survival time of mice treated with VLB alone, BLM alone and combination of both drugs was significantly prolonged compared to the control untreated mice. When VLB and BLM were combined, both treatment combinations were more effective than monochemotherapies with VLB or BLM. The best results were obtained when VLB was followed by BLM after 24 h. The DNA histogram of cells treated with VLB showed a decreased number of cells in S phase and an increased number of cells with DNA values greater than in G2M compartment compared to the control untreated cells. BLM in the dosage used inthese experiments did not affect the progression of cells through cell cycle. Both combinations of VLB and BLM produced similar cell kinetic effect as VLB alone. Conclusion. (Abstract truncated at 2000 characters.)
Objavljeno v DiRROS: 23.01.2024; Ogledov: 134; Prenosov: 30
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46. Cathepsin D and plasminogen activator inhibitor type 1 in normal, benign and alignant ovarian tissues : a preliminary reportMarina Šprem, Damir Babić, Marija Abramić, Duško Miličić, Ivan Vrhovec, Janez Škrk, Maja Osmak, 2000, izvirni znanstveni članek Povzetek: Background. The aim of the present study was to determine the concentration ofcathepsin D (Cath D) and plasminogen activator inhibitor type 1 (PAI-1) in normal ovarian tissues, benign and malignant ovarian tumor tissues, and to asses relationship between Cath D and PAI-1 content, and some clinical and pathohistological parameters. Materials and methods. Cath D contents and PAI-1concentrations were determined (using immunoradiometric ELSA-Cath D assayand commercial IMUDIND R ELISA immunoassay, respectively) in 35 samples: 10 normal ovarii, 10 benign, 10 primary malignant and 5 metastatic ovarian tumors. Results. The concentrations of Cath D were significantly higher in malignant (32.89+-14.26 pmol/mg protein ) and metastatic (31.42+-10.24 pmol/mgprotein), than in normal (13.68+-4.03 pmol/mg protein) and benign (17.89+-13.13 pmol/mg protein) ovarian tissues. There was no statistical differences in the concentrations of PAI-1 between normal, benign, malignant and metastatic tumor specimens. The concentrations of Cath D as well as PAI-1 did not correlate to the age of patients, menopausal status, parity, GOG risk group, clinical stage or pathohistological grading. Conclusion. Concentrationsof Cath D (but not PAI-1) were significantly increased in malignant and metastatic ovarian tumor tissues when compared to normal and benign ovarian tumor samples; they were independent from pathohistological andclinical parameters.
Objavljeno v DiRROS: 23.01.2024; Ogledov: 144; Prenosov: 52
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47. Comprehensive permanent remote monitoring system of a multi-span highway bridgeAndrej Anžlin, Uroš Bohinc, Doron Hekič, Maja Kreslin, Jan Kalin, Aleš Žnidarič, 2021, objavljeni znanstveni prispevek na konferenci Povzetek: As part of the reconstruction of a multi-span viaduct on a Slovenian highway, a permanent remote monitoring system with over 200 sensors was established. Several parameters are monitored on different parts of the viaduct by means of temperature sensors, accelerometers, strain gauges, long-gauge deformation and Fibre Bragg Grating (FBG) sensors. In this way strains, frequencies and temperatures on external prestressed beam cables, carbon fibre rebarsused for the flexural strengthening of a deck overhang, pier caps and prestressed beams are measured and stored into the on-site central data acquisition system. This paper presents architecture of the permanent bridge monitoring system and preliminary results of the measurements.
Ključne besede: permanent monitoring, structural health monitoring, bridge WIM, sensors, viaduct
Objavljeno v DiRROS: 22.01.2024; Ogledov: 213; Prenosov: 98
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48. Comparison of colorimetric MTT and clonogenic assays for irradiation and cisplatin treatment on murine fibrosarcoma SA-1 cellsMaja Čemažar, Darja Marolt, Mira Lavrič, Gregor Serša, 1999, izvirni znanstveni članek Povzetek: Background. The aim of our study was to determine the relationship between cell survival of SA-1 tumor cells measured by clonogenic assay and MTT assay after irradiation and cisplatin treatment. Materials and methods. Survival of SA-1 cells was measured after irradiation (2-8 Gy) and cisplatin treatment (0.05-0.5 u g/ml) by clonogenic assay performed 7 days after treatment, and byMTT assay performed on day 3, 4, 5, and 7 after the treatment. Results. The results showed good correlation between MTT assay and clonogenic assay for irradiation doses below 4 Gy. For higher doses good correlation between MTT and clonogenic assay was determined only when MTT assay was performed on day 5and 7 after the treatment. In the case of cisplatin treatment, similar pattern was observed, good correlation between IC50 values for MTT and clonogenic assay was found when MTT assay was performed on day 5 and 7 after the treatment. Conclusion. Results of our study confirmed the results of previous studies addressing this topic and further support the use of MTT testas an alternative test for clonogenic test as a predictive assay of tumourresponse to the radio or chemotherapy.
Objavljeno v DiRROS: 22.01.2024; Ogledov: 158; Prenosov: 33
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49. Adenocarcinoma skin metastases treated by electrochemotherapy with cisplatin combined with radiationGregor Serša, Maja Čemažar, Zvonimir Rudolf, Albert-Peter Fras, 1999, izvirni znanstveni članek Povzetek: Background. The aim of this study was to determine the interaction between electrochemotherapy as a means of facilitated cisplatin delivery into the cells and irradiation of adenocarcinoma skin metastases. Case report. A patient with progressive disease presenting skin metastases of tubal dedifferentiated pappilary adenocarcinoma was enrolled in the study. Skin metastases were treated by electrochemotherapy with intratumoral injection of cisplatin. Its antitumor effectiveness was compared to that of combined treatment of irradiation with electrochemotherapy. After a two week observation time, the response to treatment was comparable between the electrochemotherapy and electrochemotherapy combined with irradiation. Both ofthese treatments were more effective than irradiation alone. Furthermore, antitumor effectiveness of the combined electrochemo- and radiotherapy was found to be quicker than that of electrochemotherapy alone. Comment. This study shows that electrochemotherapy with cisplatin is also effective in the treatment of adenocarcinoma skin metastases. Inspite of the short observation time, positive interaction between radiotherapy and electrochemotherapy with cisplatin was found.
Objavljeno v DiRROS: 22.01.2024; Ogledov: 140; Prenosov: 34
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50. Cryosurgery combined with radiotherapy of tumors in miceAlbert-Peter Fras, Simona Kranjc Brezar, Maja Čemažar, Gregor Serša, 1999, izvirni znanstveni članek Povzetek: Tlle aim of this study zuas to determine antitumor effectiveness of cryosurgery alone and in comhination with radiotherapy. Cryosurgery of subcutaneous fibrosarcoma SA-1 tumors in A/J mice was moderately effective trcatmcnt. Tumor growth delay was 10.3 * 3.8 days after 5 minute treatment with nitrogen filled cryo-prohe. Shorter treatment times induced less, but dose dependent antitumor effect. In combined treat- ment, tumors were either first treated by cryosurgery for 3 minutes and then locally irradiated with 10Gy for 5 minutes, or irradiated first and thereafter treated by cryosurgery.The antitumor effectiveness of com- bined treatrnent was sequence dependent; the irradiation of tumors before cryosurgery resulted in better antitumor effect than the irradiation after cryosurgery. These results indicate that radiosensitization may not be always expected, in spite of some reports demonstrating that cryosurgery may have radiosensitizing effect in vivo, and that some other mechanisms may be involved contributing to radiationdamage when cryosurgery follows irradiation.
Objavljeno v DiRROS: 22.01.2024; Ogledov: 149; Prenosov: 40
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