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Povzetek: To purpose of the study was to analyze the results of preoperative radiochemotherapy in patients with unresectable gastric or locoregionally advanced gastroesophageal junction (GEJ) cancer treated at a single institution. Between 1/2004 and 6/2012, 90 patients with locoregionally advanced GEJ or unresectable gastric cancer were treated with preoperative radiochemotherapy at the Institute of Oncology Ljubljana. Planned treatment schedule consisted of induction chemotherapy with 5-fluorouracil and cisplatin, followed by concomitant radiochemotherapy four weeks later. Three-dimensional conformal external beam radiotherapy was delivered by dual energy (6 and 15 MV) linear accelerator in 25 daily fractions of 1.8 Gy in 5 weeks with two additional cycles of chemotherapy repeated every 28 days. Surgery was performed 4-6 weeks after completing radiochemotherapy. Following the surgery, multidisciplinary advisory team reassessed patients for the need of adjuvant chemotherapy. The primary endpoints were histopathological R0 resection rate and pathological response rate. The secondary endpoints were toxicity of preoperative radiochemotherapy and survival. Treatment with preoperative radiochemotherapy was completed according to the protocol in 84 of 90 patients (93.3%). Twenty patients (22.2%) did not undergo the surgery because of the disease progression, serious comorbidity, poor performance status or still unresectable tumour. In 13 patients (14.4%) only exploration was performed because the tumour was assessed as unresectable or diffuse peritoneal carcinomatosis was established. Fifty-seven patients (63.4%) underwent surgery with the aim of complete removal of the tumour. Radical resection was achieved in 50 (55.6%) patients and the remaining seven (7.8%) patients underwent non-radical surgery (R1 in five and R2 in two patients). In this group of patients (n = 57), pathological complete response of tumour was achieved in five patients (5.6% of all treated patients or 8.8% of all operated patients). Down-staging was recorded in 49 patients (86%), in one patient (1.8%) the stage after radiochemotherapy was unchanged while in seven patients (12.3%) the pathological stage was higher than clinical, mainly due to higher pN stage. No death was recorded during preoperative radiochemotherapy. Most grade 3 and 4 toxicities were due to vomiting, nausea and bone marrow suppression (granulocytopenia). Twentysix (45.6%) patients died due to GEJ or gastric carcinoma, one died because of septic shock following the surgery and a reason for two deaths was unknown. Twenty-eight patients (49.1%) were disease free at the time of analysis, while 29 patients (50.9%) developed the recurrence, mostly as distant metastases. At two years, locoregional control, diseasefree survival, disease-specific survival and overall survival were 82.9%, 43.9%, 56.9% and 53.9%, respectively. Preoperative radiochemotherapy was feasible in our group of patients and had acceptable toxicity. Majority of patients achieved down-staging, allowing greater proportion of radical resections (R0), which are essential for patientsʼ cure.
Ključne besede: neoadjuvant radiochemotherapy, perioperative chemotherapy, chemotherapy, adenocarcinoma, carcinoma, surgery
Objavljeno v DiRROS: 23.04.2024; Ogledov: 34; Prenosov: 6
Celotno besedilo (1,18 MB)

Povzetek: Stereotaktična radioterapija aritmij (STAR) predstavlja novo in obetavno možnost za bolnike z refraktarno prekatno tahikardijo, ki je odporna proti konvencionalnim metodam zdravljenja. STAR omogoča natančno neinvazivno ablacijo aritmogenega substrata ob minimalni prizadetosti sosednjih organov. Ta metoda zdravljenja je uporabna za bolnike, pri katerih je tarčno tkivo s katetrsko ablacijo nedosegljivo, pogosti šoki implantabilnega kardioverter-defibrilatorja pa močno nižajo njihovo kakovost življenja ali kadar sta ti metodi zdravljenja zaradi slabega zdravstvenega stanja kontraindicirani. Tarčo obsevanja (predel levega prekata) natančno opredelimo s predhodno slikovno diagnostiko, elektrokardiogramom, posnetki prekatne tahikardije in po potrebi invazivnim ali neinvazivnim elektrofiziološkim mapiranjem srca. Po pripravi na obsevanje na simulatorju sledi enkratno obsevanje z visokim odmerkom 25 Gy, ki je trenutno edina standardna frakcionacija. Bolniki obsevanje dobro prenašajo. Dosedanje raziskave so poročale o dobri učinkovitosti zdravljenja z bistvenim zmanjšanjem pogostosti epizod prekatne tahikardije in brez večjih neželenih učinkov. Poročamo o prvi skupini štirih bolnikov z visokorizično refraktarno prekatno tahikardijo, ki so bili zdravljeni s stereotaktično radioterapijo na Onkološkem inštitutu Ljubljana. Izvedba STAR se je izkazala kot učinkovita metoda z nizko stopnjo akutnih neželenih učinkov in predstavlja novo možnost obravnave te ranljive skupine bolnikov v slovenskem prostoru.
Ključne besede: stereotaktična radioterapija, aritmije, prekatna tahikardija, radioablacija srca
Objavljeno v DiRROS: 26.02.2024; Ogledov: 113; Prenosov: 35
Celotno besedilo (146,07 KB)

Povzetek: The main objective of this manuscript is to collect, classify, and compile all available data about secondary mineral sources of REEs in the South-Eastern Europe (SEE). The material is generated from the extracting and processing sector, that might be possibly transformed in the business process becoming an important raw material for another industry. The management inventory guide will strengthen communication and dissemination efforts and simultaneously contribute to Europe’s self-sufficiency and support transitioning to green and digital technology. Identification of the knowledge gaps associated with secondary sources of REEs in SEE will contribute to connections between all partners being involved at the beginning, during the lifetime of products and at the end of the life cycle, represented with deposit owners, technology developers and potential processors, producers, and potential users. At the investigated area it was found 1835 individual landfills, most of them belonging to waste rocks. The total quantity of all material in SRM is about 3.2 billion tons on an area of about 100 km2. The largest 95 individual landfills were selected as potential prospective landfills, containing about 1600 million tons of material. The estimated total potential of REEs (ΣREE) is more than 200 Kt. The largest quantities are found in landfills for coal fly ash and Cu flotation, which correspond to more than 80% of the ΣREE. Most of the promising sites are located in Serbia and North Macedonia. It has been calculated that the valorisation potential and perspectivity of REE2O3 is about 32.5 billion USD (prices from December 2022). According to the average concentrations of REEs, the most prospective are the red mud dams but their total volume is limited compared to massive amounts of coal fly ash landfills. The REEs content in all type of investigated materials, especially in coal fly ash in North Macedonia is twice as high as in other countries.
Ključne besede: secondary raw materials, ESEE, rare elements, economic prospective
Objavljeno v DiRROS: 06.02.2024; Ogledov: 146; Prenosov: 39
Celotno besedilo (12,40 MB)

Ključne besede: economic valuation, long-term investment, revenues, costs, oak stands
Objavljeno v DiRROS: 06.10.2023; Ogledov: 234; Prenosov: 80
Celotno besedilo (118,45 KB)

Povzetek: Flotation wastes are becoming a valuable secondary raw material and source of many metals and semimetals worldwide with the possibilities of industrial recycling. The flotation tailings contain oxide and sulfide minerals that have not been sufficiently stabilized and form acidic mine waters, which in turn contaminate groundwater, rivers, and reservoi6sediments. An effective way to recycle these mine wastes is to recover the metals through leaching. While the focus is on acid bioleaching by iron- and sulfur-oxidizing bacteria, alkaline leaching, and the removal of iron- containing surface coatings on sulfide minerals contribute significantly to the overall environmental efficiency of leaching. For this study, static and percolate bioleaching of copper from flotation waste at the Bor copper mine in Serbia was investigated in alkaline and then acidic environments. The aim of the study was to verify the effect of alkaline pH and nutrient stimulation on the bioleaching process and element extraction. A sample was taken from a mine waste site, which was characterized by XRF analyses. The concentration of leached copper was increased when copper oxide minerals dissolved during alkaline bioleaching. The highest copper yield during alkaline bioleaching was achieved after 9 days and reached 67%. The addition of nutrients in acidic medium enhanced the degradation of sulfide minerals and increased Cu recovery to 74%, while Fe and Ag recoveries were not significantly affected. Combined bioleaching with alkaline media and iron- and sulfur-oxidizing bacteria in acidic media should be a good reference for ecological Cu recovery from copper oxide and sulfide wastes.
Ključne besede: copper, alkaline, acidic bioleaching, secondary raw materials, open access
Objavljeno v DiRROS: 05.05.2023; Ogledov: 301; Prenosov: 151
Celotno besedilo (3,29 MB)
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