Polytechnic Pula

Abstract Radiotherapy (RT) is a cornerstone treatment for nearly 50% of cancer patients, but its curative potential and safe dosing are constrained by cumulative toxicity to surrounding healthy tissues. Delivering RT at ultra-high dose rates (FLASH-RT) represents a transformative strategy, as it appears to maintain tumor control, while sparing normal tissue. Melanoma is among the most radioresistant tumors, and skin and muscle are invariably exposed during RT, also in case of deep seated tumors. Here, we compared electron FLASH-RT and conventional RT (CONV-RT) in melanoma-bearing and naïve mice assessing tumor control, tissue integrity, and systemic homeostasis over the medium to long term. Both modalities achieved comparable tumor suppression. However, CONV-RT induced persistent skin damage, dermal fibrosis, muscle dysfunction and systemic inflammatory-metabolic alterations, while FLASH-RT largely spared normal tissue and systemic balance. Bulk RNA sequencing revealed striking differences: FLASH induced minimal transcriptional disruption in skin and muscle, whereas CONV-RT triggered thousands of differentially expressed genes, including massive activation of fibrosis, inflammation, cell death-related pathways in skin, and broad dysregulation of genes linked to muscle function, remodeling and the unfolded protein response. Histological and ultrastructural analyses corroborated the findings, showing reduced immune infiltration in the skin and preserved tissue architecture both in skin and muscle following FLASH. In conclusion our study not only confirms the protective nature of FLASH but also provides novel mechanistic insights into the cascade linking local injury to systemic dysfunction under CONV-RT, reinforcing the translational potential of FLASH to expand the therapeutic window of radiotherapy. One Sentence Summary Comparative analysis of FLASH and conventional radiotherapy in a murine model of melanoma and naïve mice - Therapeutical efficacy, local and systemic effects.

Child abuse remains a persistent and grave issue worldwide, with significant social and economic implications. In Malaysia, despite various measures, child abuse rates have shown a concerning upward trend. Understanding the economic factors that contribute to this issue is essential for crafting effective interventions. This study utilizes the non-linear ARDL method to investigate the relationship between poverty, economic growth, unemployment, and child abuse in Malaysia from 1989 to 2020. The results reveal significant impacts of variations in poverty, economic output, and unemployment on child abuse rates. Specifically, higher unemployment rates are associated with higher child abuse rates over the long term, while lower unemployment rates may lead to lower rates of child abuse. Increases in poverty have been correlated with decreases in child abuse. Both positive and negative fluctuations in economic growth have direct and pronounced effects on the upward trend of child abuse rates. Interestingly, while a positive shock in economic growth increases child abuse, a negative shock mitigates it in the short run. Negative trends in poverty correspond to an increase in abuse rates. These findings highlight the complex relationship between macroeconomic factors and child abuse rates. They underscore the importance of government interventions to address this issue and promote the well-being and happiness of children as the economy advances. Therefore, policymakers are encouraged to prioritize child protection and abuse prevention as interconnected goals. This can be achieved by implementing interventions that address underlying parental stressors, such as offering support for managing work-related stress, reducing the stigma associated with unemployment, and ensuring access to mental health and social support services..

The aim of this study was to determine whether body mass index and age had an impact on functional recovery two years after total knee replacement. The research was conducted at the Lovran Hospital of Orthopedics and Traumatology, School of Medicine, University of Rijeka, Croatia. Study sample included patients who underwent total knee replacement surgery with median parapatellar approach in 2019. Morphological measurements, knee range of motion and WOMAC questionnaire score were examined before and two years after surgery. Descriptive statistics was used for gender, age and body mass index, and inferential statistics was employed to check the correlation of recovery measured by changes in the WOMAC score and change in the range of motion results with age and body mass index. According to study results, male and female patients did not differ in body mass index (t=1.184; p>0.05). There was no statistically significant correlation of functional recovery of the patients with age (p=0.556), or between body mass index and differences in the range of motion (p=0.927) from flexion to extension. The study indicated that knee arthroplasty and thus the impact on functional recovery had an equally good effect regardless of age. In patients who had flexion contracture before surgery, the surgery improved motion amplitude.

Abstract Aluminium alloy stack materials offer good strength-to-weight ratio and are used for high strength airframe structures. For the panels to be joined, numerous holes have to be drilled and due to structure size mobile drilling heads are used. The drilling process releases lubricant oil which becomes airborne or collects on the shop-floor and presents a health and safety hazard. Avoiding this oil release is therefore a major driver for developing dry drilling processes. However, drilling aluminium alloys in the absence of cutting fluids is a challenging task due to its tendency to adhere to the cutting tool, and the high thermal conductivity of the workpiece. Owing to their low coefficient of friction, carbon-based coatings are an option to improve the machinability of aluminium alloys. This paper presents an industrial collaboration study on the performance of carbon-based coatings in dry drilling aluminium alloy 2024 and 7150 stacks. CVD Diamond, a hard DLC, Doped MoS2 and doped amorphous carbon (Doped a-C) were evaluated in comparison with an uncoated WC drills. Coating performance was assessed in terms of tool wear, hole diameter, and surface roughness. The results revealed that CVD diamond coated drills outperformed other coatings in terms of tool wear and hole quality. The coating enabled lower aluminium pick-up on the drills as well as minimised variations in diameter deviation and hole surface roughness. The work shows the capability for dry drilling of stacked aluminium alloys and hence eliminating the health and safety risk associated with use of oil in mobile drilling heads.

Ion-exchange chromatography is still one of the most popular protein separation techniques. Before chromatographic separation, the high salt concentration in various samples necessitates additional steps. Therefore, low salt tolerance of ion-exchange resins is a drawback that needs to be addressed. Herein, the differences in salt tolerance and hydrophobicity of strong cation-exchange TOYOPEARL resins of sulfonium and sulfate-types were investigated. Despite only a minor structural difference, differences in selectivity and salt tolerance between the sulfate and sulfonic groups were detected. In silico calculations were also carried out for model substances representing the sulfonium and sulfate groups, wherein significant differences in hydrophobicity was observed. These experiments confirmed the hypothesis that the salt tolerance, higher affinity, and selectivity for certain vitamin K dependent clotting factors are interrelated and dependent on the presence of the sulfate group. Separation of clotting factor IX from the prothrombin complex concentrate further to confirmed the affinity for these proteins. The results show that the use of only a resin with the sulfate ligand and not with the sulfonic acid ligand allows for a facile and rapid separation of clotting factor IX and other vitamin K dependent clotting factors.

Aluminum alloys are widely applied in automotive, aircraft, food, and building industries. Multicomponent technical AlSi9MgMn alloy is primarily intended for high cooling rate technology. Controlled addition of alloying elements such as iron and manganese as well as magnesium can improve mechanical and technological properties of the final casting depending on the cooling conditions during solidification. The aim of this investigation is the characterization of AlSi9MgMn alloy microstructure and mechanical properties at lower cooling rates than those for which this alloy was primarily developed. Thermodynamic calculation and thermal analyses revealed solidification sequence in correlation to the microstructure investigation as follows: development of primary dendrite network, precipitation of high temperature Al15(Mn,Fe)3Si2 and Al5FeSi phases, main eutectic reaction, precipitation of intermetallic Al8Mg3FeSi6 phase, and Mg2Si as a final solidifying phase. Influence of microstructure features investigation and cooling rate reveals significant Al15(Mn,Fe)3Si2 morphology change from Chinese script morphology at low, irregular broken Chinese script morphology at medium, and globular morphology at high cooling rate. High manganese content in AlSi9MgMn alloy together with high cooling rate enables the increase of Fe+Mn total amount in the intermetallic Al15(Mn,Fe)3Si2 phase and encourage favourable morphology development, all resulting in enhanced mechanical properties in as-cast state.