https://www.um.edu.mt/library/oar/handle/123456789/906 Thu, 17 Sep 2026 13:43:16 GMT 2026-09-17T13:43:16Z https://www.um.edu.mt/library/oar/handle/123456789/148796 Title: “Could patient age and gender, along with mass size, be predictive factors for benign kidney tumors?” : A retrospective analysis of 307 consecutive single renal masses treated with partial or radical nephrectomy Authors: Baio, Raffaele; Molisso, Giovanni; Caruana, Christian; Di Mauro, Umberto; Intilla, Olivier; Pane, Umberto; D’Angelo, Costantino; Campitelli, Antonio; Pentimalli, Francesca; Sanseverino, Roberto Abstract: Due to the increased use of common and non-invasive abdominal imaging techniques over the last few decades, the diagnosis of about 60% of renal tumors is incidental. Contrast-enhancing renal nodules on computed tomography are diagnosed as malignant tumors, which are often removed surgically without first performing a biopsy. Most kidney nodules are renal cell carcinoma (RCC) after surgical treatment, but a non-negligible rate of these nodules may be benign on final pathology; as a result, patients undergo unnecessary surgery with an associated significant morbidity. Our study aimed to identify a subgroup of patients with higher odds of harboring benign tumors, who would hence benefit from further diagnostic examinations (such as renal biopsy) or active surveillance. We performed a retrospective review of the medical data, including pathology results, of patients undergoing surgery for solid renal masses that were suspected to be RCCs (for a total sample of 307 patients). Owing to the widespread use of common and non-invasive imaging techniques, the incidental diagnosis of kidney tumors has become increasingly common. Considering that a nonnegligible rate of these tumors is found to be benign after surgery at pathological examination, it is crucial to identify features that can correctly diagnose a mass as benign or not. According to our study results, female sex and tumor size ≤ 3 cm were independent predictors of benign disease. Contrary to that demonstrated by other authors, increasing patient age was also positively linked to a greater risk of malign pathology. Sun, 01 Jan 2023 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/148796 2023-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/144069 Title: Modelling indoor household PM2.5 using positive matrix factorization and machine learning algorithms Abstract: People tend to spend most of their time indoors, yet the concentration and composition of indoor fine particulate matter (PM2.5) remain poorly understood in the Maltese Islands, with existing receptor modelling studies focusing solely on ambient air. The first objective of this study was to carry out long-term indoor air sampling of PM2.5 followed by chemical characterisation, in order to identify and quantify the main natural and anthropogenic sources of indoor PM2.5 at an urban background site in Malta using Positive Matrix Factorisation (PMF). The second objective was to explore the use of Machine Learning (ML) algorithms to model and predict indoor PM2.5 concentrations in several households in Malta and Gozo. PMF was used to identify and quantify the major sources of indoor PM2.5. Quartz and PTFE filters were collected and analysed gravimetrically and chemically using ICP-MS, IC, and an OC-EC aerosol analyser to determine concentrations of PM2.5, 18 elements, 5 ions, organic carbon (OC), and elemental carbon (EC). Eight contributing factors were identified, seven outdoor sources and one indoor source, contributing 68% and 26% to indoor PM2.5, respectively. Cooking and e-cigarette use were the main contributors to the indoor factor. Uniquely for Malta, a fireworks factor was isolated indoors, responsible for most of the measured Sb and Ba, raising concerns due to the toxicity of these elements. An RF-SHAP model was integrated with the indoor PMF model to investigate the influence of key drivers on indoor PM2.5 concentrations. An outdoor PMF analysis was also conducted, and a corresponding RF-SHAP model (CV RMSE: 2.79 µg m−3; R²: 0.80) was used to refine the outdoor source contributions. Transboundary contributions (Saharan dust and ammonium sulfate) were higher outdoors (58%) than indoors (33%) due to reduced infiltration when windows are closed. Local anthropogenic sources (Industrial, Fireworks, Traffic, Shipping) contributed more to outdoor PM2.5 (33%) than indoor (25%), with increased indoor infiltration during warmer months coinciding with peak fireworks activity. For the second objective, continuous PM measurements were taken using aerosol spectrometers at seven non-smoking residences. RF and XGBoost models were developed to predict indoor PM2.5 at six-hourly intervals. At sites with low indoor PM generation, predictions were mainly influenced by outdoor PM1 levels. At a site with high indoor emissions, indoor relative humidity was a key predictor, especially during cooking. The RF model performed best overall (RMSE: 30.65 µg m−3; IOA: 0.66). Description: Ph.D.(Melit.) Mon, 01 Jan 2024 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/144069 2024-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/143309 Title: Storage stability and antioxidant activity of astaxanthin and beta-carotene as affected by the architecture of O/W emulsions of milk proteins Authors: Habtegebriel, Haileeyesus; Tazart, Zakaria; Farrugia, Claude; Valdramidis, Vasilis Abstract: Astaxanthin and β-carotene are among the potential anti-oxidant carotenoids with strong health promoting features. However, their sensitivity to light, heat and mechanical forces limit their application in food processing and storage conditions. The design of food matrix system, such as emulsions, that could prevent them from exposure to environmental factors will be utmost importance to slow down their degradation. In this study, O/W emulsion systems containing sunflower oil were prepared by applying ultrasound treatment and using different stabilizers (i.e. whey protein isolate (WPI) and sodium caseinate; NaCAS), co-surfactants (pectin and lecithin) while their performance against physical and chemical stability were investigated. The WPI– lecithin system produced emulsion droplets with Average diameter in the range of 560–2900 nm with a zeta-potential in the range of (−31) – (−34) mV, whereas the NaCAS – lecithin systems produced emulsion droplets with average diameter in the range of 230–240 nm and zeta potential of (−44) – (−48) mV. These values have a direct effect on the physical stability and chemical stability of the carotenoids in the emulsions. Astaxanthin was found to be more sensitive than β-carotene to ultrasound processing conditions. The designed emulsion systems slowed down the degradation of the carotenoids and maintained their DPPH scavenging properties during storage with astaxanthin loaded emulsions exhibiting better DPPH activity than β-carotene loaded emulsions. Mon, 01 Jan 2024 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/143309 2024-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/141614 Title: Molecular logic gates as fluorescent markers and DNA binding agents Abstract: N/A Description: Ph.D.(Melit.) Sun, 01 Jan 2023 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/141614 2023-01-01T00:00:00Z