981. A calcified cervical intervertebral disc in child and a thoracic disc calcification in an adult with posterior herniation-radiographic, computed tomography and magnetic resonance imaging findingsVladimir Jevtič, 2004, professional article Abstract: Izhodišča. Kalcifikacije nukleusa pulposusa pri otroku so sorazmerno redek, vendar dobro znan klinični sindrom, ki se običajno pojavlja na vratni hrbtenici. Natančen vzrok še vedno ni znan. Kalcifikacije medvretenčne ploščice odraslega so večinoma posledica degeneracije in se pojavIjajo v višini spodnje prsne in zgornje ledvene hrbtenice. Pri obeh entitetah lahko nastane resna komplikacija, posteriorna hernijacija kalcificiranega diskusa. Prikaz primera. Prikazana sta dva primera kalcificirane medvretenčne ploščice,prvi pri 7-letnem otroku v višini C7-T1 ter drugi pri 45-letni ženskiv višini T11-T12, oba z razsežno dorzalno hernijacijo. V prvem primeru je dosežena remisija s konservativnom zdravljenjem. Na podlagi analize radiografskih, računalniškotomografskih ter magnetnoresonančnih (MRI) spremembsmo ugotovili podobnosti in razlike med obema entitetama. Zaključki. Masivna dorzalna hernijacija kalcificiranega nukleusa pulposusa pri otroku je uspešno zdravljena konzervativno. Izginotje kliničnih znakov je sledilo hitri resorpciji kalcificirane diskus hernije. Pri odraslem po konzervativnem zdravljenju ni prišlo do resorpcije kalcificirane diskus hernije in kliničnih znakov izboljšanja. Z MRI je možen zgodnejši prikaz kalcifikacij. Tudi razširitev prizadetih medvretenčnih ploščic pri otroku je boljše prikazana z MRI. Razširitev kalcificiranih medvretenčnih ploščic podpira teorijo zvišanegaintradiskalnega pritiska kot vzroka rupture anulusa fibrozusa in posledične hernijacije nukleusa pulposusa.
Published in DiRROS: 07.02.2024; Views: 217; Downloads: 59
 Full text (301,27 KB) |
982. Annular pancreas causing extrahepatic biliary obstructionMateja Ogulin, Breda Jamar, 2004, professional article Abstract: Izhodišča. Anularni pankreas, redka prirojena anomalija, je trak pankreatičnega tkiva, ki obkroža dvanajstnik ali izvenjetrni žolčni vod. Prikazujemo primer anularnega pankreasa, ki je povzročil izvenjetrno zaporo odtoka žolča. Prikaz primera. 46-letna ženska je prišla v urgentno ambulanto zaradi nenadnih bolečin v trebuhu, bruhanja in zlatenice. V zadnjih šestih letih je občasno opazila rumenkasto obarvanje kože, v zadnjem letu pa je občutila napetost v zgornjem delu trebuha, predvsem po mastnih obrokih. Zaključki. Dve ultrazvočni preiskavi, prva pred šestimi meseci, sta pokazali razširitev glavnega izvenjetrnega voda in jetrnih žolčnih izvodil. Vzrok za razširitev je ostal nejasen, tudi po endoskopski ultrazvočni preiskavi. Pri operaciji so našli skoraj popolno zaporo izvenjetrenega žolčnega voda, ki jo je povzročal traček pankreatičnega tkiva.
Published in DiRROS: 07.02.2024; Views: 276; Downloads: 49
Full text (243,96 KB) |
983. Demonstration of evolution of hemispherical spondysclerosis by contrast enhanced Gd-DTPA magnetic resonance imagingVladimir Jevtič, Natalija Majcen, 2004, original scientific article Abstract: Izhodišča. Namen študije je bil ugotoviti vrednost slikovne magnetne resonance(MRI) s paramagnetnim kontrastnim sredstvom Gd-DTPA v prikazu napredovanja hemisferične spondiloskleroze (HSS). Bolniki in metode. Pri 18 bolnikih s kronično bolečino v križu in tipičnimi radiografskimi znaki HSS smoopravili Gd-DTPA MRI lumbalne hrbtenice. Primerjali smo morfološke spremembe in spremembe intenzitete signala z radiografskimi znaki HSS. Rezultati. Na podlagi MRI smo primere razdelili v tri skupine. V prvi skupini je bilo radiografsko področje osteoskleroze hipointenzivno na T1-poudarjenih spin-eho slikah, hiperintenzivno na T2-poudarjenih slikah in je kazalo difuznonabiranje paramagnetnega kontrastnega sredstva. Opisane spremembe so bile združljive s kostnim edemom in hiperemijo. V drugi skupini so bili robovivretenc na vseh slikovnih sekvencah hiperintenzivni, obdani s hipointenzivno cono in se v njih ni nabiralo kontrastno sredstvo. Opisano je izražalo kombinacijo maščevja in kostne skleroze. Pri preostalih bolnikih so MRI znaki predstavljali kombinacijo sprememb vidnih v prvi in drugi skupini. Zaključki. Gd-DTPA MRI kaže zapletene histološke spremembe v teku napredovanjaHSS. Spremljanje značilnih MRI znakov ima lahko klinični pomen prisledenju bolezni.
Published in DiRROS: 07.02.2024; Views: 283; Downloads: 66
Full text (359,18 KB) |
984. Mechanisms of premature fracture in modular neck stems made of CoCrMo/Ti6Al4V and Ti6Al4V/Ti6Al4V alloyDrago 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: 323; Downloads: 172
Full text (5,12 MB)
This document has many files! More... |
985. Grain size distribution of DP 600 steel using single-pass asymmetrical wedge testUrška Klančnik, Peter Fajfar, Jan Foder, Heinz Palkowski, Jaka Burja, Grega Klančnik, 2023, original scientific article Keywords: wedge test, hot-rolling, grain size distribution, dual-phase steel
Published in DiRROS: 07.02.2024; Views: 288; Downloads: 114
Full text (4,64 MB)
This document has many files! More... |
986. Thermal fatigue degradation progress in SiMo ductile cast iron under oxidation conditionsMilan Terčelj, Jaka Burja, Goran Kugler, Primož Mrvar, 2023, original scientific article Keywords: metallurgical engineering, exhaust manifolds, cast irons, casting, microscopic characterization and microanalysis, thermal fatigue, material defect, microstructural control
Published in DiRROS: 07.02.2024; Views: 323; Downloads: 184
Full text (36,47 MB)
This document has many files! More... |
987. 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: 382; Downloads: 137
Full text (1,94 MB)
This document has many files! More... |
988. Metal artefacts and remains of armour from Kozlov Rob castle : metallurgical analyses as a tool for identification and interpretation of fragmentary archaeological findsJakob Kraner, Tomaž Lazar, Miha Mlinar, Jaka Burja, 2023, original scientific article Keywords: archaeology, castle, Kozlov Rob, Slovenia, armour, helmet, metallography
Published in DiRROS: 07.02.2024; Views: 295; Downloads: 120
Full text (3,92 MB)
This document has many files! More... |
989. |
990. Study on dissolution of Ba-containing inoculant in ductile cast iron melt and nucleation of graphiteMarica Tonkovič-Prijanovič, Primož Mrvar, Jaka Burja, Črtomir Donik, Mitja Petrič, 2023, original scientific article Keywords: inoculant, inoculant dissolving, reaction zone, phase composition, graphite nucleation, ductile cast iron, barium inoculant
Published in DiRROS: 07.02.2024; Views: 228; Downloads: 131
Full text (17,37 MB)
This document has many files! More... |
