ROLE OF OBESITY IN THE DEVELOPMENT OF ACUTE PROMYELOCYTIC LEUKEMIA (APL)

Obesity is a pathological condition characterized by an augmented presence of fat mass in the body, and a known risk factor for many cancer types. Clinical data have shown that the incidence of acute promyelocytic leukaemia (APL) is strongly correlated with obesity. APL is characterized by reciprocal translocation between chromosomes 15 and 17 resulting in the formation of the PML/RAR\u3b1 oncoprotein. However, the molecular mechanisms explaining the effects of obesity on APL development have not been elucidated. To recapitulate clinical observations, we characterized a mouse model of diet-induced obesity using transgenic mice constitutively expressing PML/RAR\u3b1 in the hematopoietic system (PML/RAR\u3b1 KI mice) and wild type mice as a control. Mice were fed standard diet (SD) or high fat diet (HFD), and leukaemia-free survival was monitored. We observed that HFD-fed PML/RAR\u3b1 KI mice developed leukaemia earlier and with higher penetrance than SD-fed mice. We evaluated the extent of DNA damage in hematopoietic stem cells (HSC) after four months of diet. We demonstrated that HFD-fed PML/RAR\u3b1 KI mice presented a 40% increase of DNA damage in HSCs as compared to SD-fed PML/RAR\u3b1 mice. However, this was not associated with an increased mutational load as revealed by whole genome sequencing-based method. We investigated whether HFD confers a proliferative advantage to PML/RAR\u3b1 bone marrow using colony forming assays. Indeed, we observed that HFD PML/RAR\u3b1 bone marrow has a higher clonogenicity than bone marrow from SD-fed mice. Finally, we demonstrated that linoleic acid (LA), which is the main component of HFD increases PML/RAR\u3b1 enhanced self-renewal

Energy efficiency and integration of urban electrical transport systems: EVS and metro-trains of two real European lines

Transport is a main source of pollutants in cities, where air quality is a major concern. New transport technologies, such as electric vehicles, and public transport modalities, such as urban railways, have arisen as solutions to this important problem. One of the main difficulties for the adoption of electric vehicles by consumers is the scarcity of a suitable charging infrastructure. The use of the railway power supplies to charge electric vehicle batteries could facilitate the deployment of charging infrastructure in cities. It would reduce the cost because of the use of an existing installation. Furthermore, electric vehicles can use braking energy from trains that was previously wasted in rheostats. This paper presents the results of a collaboration between research teams from University of Rome Sapienza and Comillas Pontifical University. In this work, two real European cases are studied: an Italian metro line and a Spanish metro line. The energy performance of these metro lines and their capacity to charge electric vehicles have been studied by means of detailed simulation tools. Their results have shown that the use of regenerated energy is 98% for short interval of trains in both cases. However, the use of regenerated energy decreases as the train intervals grow. In a daily operation, an important amount of regenerated energy is wasted in the Italian and Spanish case. Using this energy, a significant number of electric vehicles could be charged every day

Mapping the structural diversity of C60 carbon clusters and their infrared spectra

The current debate about the nature of the carbonaceous material carrying the infrared (IR) emission spectra of planetary and proto-planetary nebulae, including the broad plateaus, calls for further studies on the interplay between structure and spectroscopy of carbon-based compounds of astrophysical interest. The recent observation of C60 buckminsterfullerene in space suggests that carbon clusters of similar size may also be relevant. In the present work, broad statistical samples of C60 isomers were computationally determined without any bias using a reactive force field, their IR spectra being subsequently obtained following local optimization with the density-functional-based tight-binding theory. Structural analysis reveals four main structural families identified as cages, planar polycyclic aromatics, pretzels, and branched. Comparison with available astronomical spectra indicates that only the cage family could contribute to the plateau observed in the 6-9 micron region. The present framework shows great promise to explore and relate structural and spectroscopic features in more diverse and possibly hydrogenated carbonaceous compounds, in relation with astronomical observations

Assessment of the worthwhileness of efficient driving in railway systems with high-receptivity power supplies

Eco-driving is one of the most important strategies for significantly reducing the energy consumption of railways with low investments. It consists of designing a way of driving a train to fulfil a target running time, consuming the minimum amount of energy. Most eco-driving energy savings come from the substitution of some braking periods with coasting periods. Nowadays, modern trains can use regenerative braking to recover the kinetic energy during deceleration phases. Therefore, if the receptivity of the railway system to regenerate energy is high, a question arises: is it worth designing eco-driving speed profiles? This paper assesses the energy benefits that eco-driving can provide in different scenarios to answer this question. Eco-driving is obtained by means of a multi-objective particle swarm optimization algorithm, combined with a detailed train simulator, to obtain realistic results. Eco-driving speed profiles are compared with a standard driving that performs the same running time. Real data from Spanish high-speed lines have been used to analyze the results in two case studies. Stretches fed by 1 × 25 kV and 2 × 25 kV AC power supply systems have been considered, as they present high receptivity to regenerate energy. Furthermore, the variations of the two most important factors that affect the regenerative energy usage have been studied: train motors efficiency ratio and catenary resistance. Results indicate that the greater the catenary resistance, the more advantageous eco-driving is. Similarly, the lower the motor efficiency, the greater the energy savings provided by efficient driving. Despite the differences observed in energy savings, the main conclusion is that eco-driving always provides significant energy savings, even in the case of the most receptive power supply network. Therefore, this paper has demonstrated that efforts in improving regenerated energy usage must not neglect the role of eco-driving in railway efficiency

Exploring the Impact of and Perceptions about Interactive, Self-Explaining Environments in Molecular-Level Animations

This mixed-method study investigates the effects of interactivity in animations of a molecular-level process and explores perceptions about the animated learning tool used. Treatments were based on principles of cognitive psychology designed to study the main effects of treatment and spatial ability and their interaction. Results with students (n = 189) showed that science majors scored higher than non-science majors in retention measures (i.e., structure and function) but not in transfer. Significant main effects were found for treatment in function questions and spatial ability in structure questions. There was a significant interaction between treatment and spatial ability in structure questions. Additionally, in this study participants believed the key and the motion of ions and molecules were the most helpful parts of the animation. This study shows that students perceive the animations as being supportive of their learning, suggesting that animations do have a role in science classrooms

Torsional response and stiffening of individual multi-walled carbon nanotubes

We report on the characterization of torsional oscillators which use multi-walled carbon nanotubes as the spring elements. Through atomic-force-microscope force-distance measurements we are able to apply torsional strains to the nanotubes and measure their torsional spring constants and effective shear moduli. We find that the effective shear moduli cover a broad range, with the largest values near the theoretically predicted value. The data also suggest that the nanotubes are stiffened by repeated flexing.Comment: 4 page

Perception, knowledge and attitude towards childhood fever: A survey among final-year medical students

Aims: Undue concerns about the consequences of fever and its inappropriate management have been documented worldwide among physicians. However, no data exist on medical students. We investigated the perception, knowledge and attitude towards childhood fever among final-year medical students. Methods: Between June and September 2021, final-year medical students of six Italian universities were invited to complete an online survey on their conceptions and attitude towards pharmacological and non-pharmacological management of childhood fever. History of relevant personal or second-hand experience with childhood fever was also addressed. Both quantitative and qualitative approaches were used. Results: Of 1095 (69%) final-year medical students, 756 completed the survey. Many students believe that high fever might cause brain damage, would recommend physical methods and alternate two drugs for fever. Most students do not think that fever has mainly beneficial effects. In Northern Italy, students are less likely to believe that fever might lead to brain damage (OR 0.55, 95% CI 0.33-0.94), and in Southern Italy students are more likely to advise physical methods (OR 1.77, 95% CI 1.22-2.57) and less likely to believe that fever has mainly beneficial effects (OR 0.55, 95% CI 0.39-0.77). History of a relevant personal episode of fever during childhood was not associated with these outcomes. Conclusions: Misconceptions about fever are common among final-year medical students in Italy. Cultural factors rather than individually learned traits might underlie these beliefs. Medical students are a promising target for educational interventions to improve childhood fever management

Atomistic Simulations of Nanotube Fracture

The fracture of carbon nanotubes is studied by atomistic simulations. The fracture behavior is found to be almost independent of the separation energy and to depend primarily on the inflection point in the interatomic potential. The rangle of fracture strians compares well with experimental results, but predicted range of fracture stresses is marketly higher than observed. Various plausible small-scale defects do not suffice to bring the failure stresses into agreement with available experimental results. As in the experiments, the fracture of carbon nanotubes is predicted to be brittle. The results show moderate dependence of fracture strength on chirality.Comment: 12 pages, PDF, submitted to Phy. Rev.