Study of the Displacement per Atom in the n-alpha reaction on MgB2

In the frame of the High-Luminosity LHC*) project (Working Package 6.4, dedicated to the energy deposition and material studies), the effects of the energy deposition from the 7+7 TeV p-p debris on the High Temperature Superconducting Links (made of MgB2) is evaluated. This paper is focused on the effect of the n-alpha reaction on MgB2 and the determination of the induced Displacement per Atom (DPA). The contribution of the single component of the reaction i.e. neutrons, alpha particles and lithium atoms on the DPA is evaluated

Evaluation of the shiedling in the bunker for the superconducting cavity test at LASA

In the LASA (Laboratorio Acceleratori e Superconduttività Applicata) laboratory of the Milan section of INFN (Istituto Nazionale di Fisica Nucleare) a facility for testing superconducting cavities is operating. The possibility to operate with a generation of radiation up to 10 MeV and more requires a careful evaluation of the shielding efficiency of the existing bunker The calculation was performed with the FLUKA code, the whole cryostat, bunker and ceiling of the building was taken into account. Two hypothesis for the radiation source have been adopted to carry out the calculations: the very conservative hypothesis of 10 MeV electron pencil beam, and the second hypothesis (maybe more realistic) of an isotropic 10 MeV electron source. In the less conservative hypothesis a safe operation is guarantee by the foreseen shielding. The simulations show that even in the most conservative hypothesis a negligible amount of photons can exit the bunker, without interaction with the simulated detectors. In the future, at the starting of the tests in the upgraded configuration, direct measurements will be used to definitely check the shielding adopted

Surgical outcome and indicators of postoperative worsening in intra-axial thalamic and posterior fossa pediatric tumors: Preliminary results from a single tertiary referral center cohort

Background: Shared indications about the best management of intra-axial thalamic (IAT) and posterior fossa (PF) pediatric tumors are still lacking. The aim of this study was to analyze neurosurgical outcome in these tumors and to investigate factors associated with postoperative worsening. Methods: A retrospective single-center study on IAT and PF pediatric tumor patients treated surgically over a 7-year period was conducted. The Lansky Scale (LS) was used to assess patients' functional status. Surgical complexity was graded with the Milan Complexity Scale (MCS). The following analyses were performed: a longitudinal analysis of the preoperative, discharge, and 3 months' follow-up (FU) LS, a comparison between improved/unchanged and worsened patients, and an analysis of the predictive value of single MCS items. Results: 37 cases were collected: 20 PF and 17 thalamic. Mean MCS score was 6 ± 1.7. Mean preoperative, discharge and FU LS were 80.8, 74.6 and 80.3 respectively. Surgical mortality was 0%.The longitudinal analysis showed a neurological worsening at discharge compared to preoperative status (p = 0.011) and an improvement at FU compared to discharge (p < 0.004), both statistically significant. None of the variables analyzed showed a significant predictive value of early postoperative change; however, higher MCS scores were associated with a greater risk of worsening. Conclusions: The surgical management of IAT and PF pediatric brain tumors remains challenging; early postoperative worsening is possible, but most deficits tend to improve at FU. The MCS seems to be a valuable tool to estimate the risk of early postoperative worsening and to facilitate parents' informed consent

BriXs ultra high fluxinverse compton source based on modified push-pull energy recovery linacs

We present a conceptual design for a compact X-ray Source BriXS (Bright and compact X-ray Source). BriXS, the first stage of the Marix project, is an Inverse Compton Source (ICS) of X-ray based on superconducting cavities technology for the electron beam with energy recirculation and on a laser system in Fabry-Pérot cavity at a repetition rate of 100 MHz, producing 20–180 keV monochromatic X-Rays devoted mainly to medical applications. An energy recovery scheme based on a modified folded push-pull CW-SC twin Energy Recovery Linac (ERL) ensemble allows us to sustain an MW-class beam power with almost one hundred kW active power dissipation/consumption

Molecular Investigation on a Triple Negative Breast Cancer Xenograft Model Exposed to Proton Beams

Specific breast cancer (BC) subtypes are associated with bad prognoses due to the absence of successful treatment plans. The triple-negative breast cancer (TNBC) subtype, with estrogen (ER), progesterone (PR) and human epidermal growth factor-2 (HER2) negative receptor status, is a clinical challenge for oncologists, because of its aggressiveness and the absence of effective therapies. In addition, proton therapy (PT) represents an effective treatment against both inaccessible area located or conventional radiotherapy (RT)-resistant cancers, becoming a promising therapeutic choice for TNBC. Our study aimed to analyze the in vivo molecular response to PT and its efficacy in a MDA-MB-231 TNBC xenograft model. TNBC xenograft models were irradiated with 2, 6 and 9 Gy of PT. Gene expression profile (GEP) analyses and immunohistochemical assay (IHC) were performed to highlight specific pathways and key molecules involved in cell response to the radiation. GEP analysis revealed in depth the molecular response to PT, showing a considerable immune response, cell cycle and stem cell process regulation. Only the dose of 9 Gy shifted the balance toward pro-death signaling as a dose escalation which can be easily performed using proton beams, which permit targeting tumors while avoiding damage to the surrounding healthy tissue

Diagnostic and surgical management of primary central nervous system angioleiomyoma: A case report and literature review

Angioleiomyoma (ALM) is a benign smooth muscle neoplasm that mainly occurs in lower extremities subcutaneous tissue and generally affects middle-aged adults. This tumor histotype may rarely localize intracranially, although only a few cases have been described in the literature. We report a case of intracranial ALM, whose differential diagnosis has been particularly challenging, and firstly provide a comprehensive radiological and intra-operative evaluation of a such rare entity. This represents also the first report of the use of intraoperative confocal microscopy in ALM and the first documented short-term recurrence. At this regard, a scoping literature review has been conducted with the aim of presenting the major clinical and diagnostic features along with the proposed therapeutic strategies

Quality of Life, Disability, Well-Being, and Coping Strategies in Patients Undergoing Neurosurgical Procedures: Preoperative Results in an Italian Sample

Background. The aim of this paper is to present the preliminary results of QoL, well-being, disability, and coping strategies of patients before neurosurgical procedure. Methods. We analysed data on preoperative quality of life (EUROHIS-QoL), disability (WHODAS-II), well-being (PGWB-S), coping strategies (Brief COPE), and functional status (KPS score) of a sample of patients with brain tumours and cerebrovascular and spinal degenerative disease admitted to Neurological Institute Carlo Besta. Statistical analysis was performed to illustrate the distribution of sociodemographic and clinical data, to compare mean test scores to the respective normative samples, and to investigate the differences between diagnoses, the correlation between tests, and the predictive power of sociodemographic and clinical variables of QoL. Results. 198 patients were included in the study. PGWB-S and EUROHIS-QoL scores were significantly lower than normative population. Patients with spinal diseases reported higher scores in WHODAS-II compared with oncological and cerebrovascular groups. Finally sociodemographic and clinical variables were significant predictors of EUROHIS-QoL, in particular PGWB-S and WHODAS-II. Conclusion. Our preliminary results show that preoperatory period is critical and the evaluation of coping strategies, quality of life, disability, and well-being is useful to plan tailored intervention and for a better management of each patient

Mathematical Modelling of the Impact of Liquid Properties on Droplet Size from Flat Fan Nozzles

Flat fan nozzles atomize crop protection products, breaking them into droplets. Droplet size matters - smaller droplets give better perfor- mance, but very small droplets drift. We want to use mathematical models to better understand how liquid properties affect droplet size. There are three types of breakup: wavy sheet, perforation, and rim. In wavy sheet breakup, increasing viscosity or surface tension increases droplet size. To investigate further, we carry out direct numerical simulations of jet breakup, which show that suface tension has little effect, but increasing viscosity leads to fewer droplets. Decreasing the jet velocity also results in fewer droplets, with a wider size distribution. Each type of breakup involves primary breakup into cylinders of fluid, then secondary breakup into droplets. We thus consider the breakup of a cylinder of fluid. Direct numerical simulations suggest that within the tested parameter range viscosity has little impact on droplet size, however it does influence the timescale on which the instability evolves considerably. Linear stability analysis suggests that increasing viscosity increases the wavelength of the most unstable mode, which we expect leads to larger droplets, and that it reduces the rate of breakup. Perforations - holes in the sheet - also lead to breakup. We find how the length fraction of the sheet that is void changes with time. After breakup, the droplets continue to evolve. We develop a model, based on a transport equation, for this process. A key parameter is the breakup rate constant - larger values lead to more breakup, fewer large droplets, and a narrower size distribution. Together, these mathematical approaches improve our understanding of how droplets form, and can be used to guide experimental work

Conceptual Design of a Soft X‐ray SASE‐FEL Source

FELs based on SASE are believed to be powerful tools to explore the frontiers of basic sciences, from physics to chemistry to biology. Intense R&D programs have started in the USA and Europe in order to understand the SASE physics and to prove the feasibility of these sources. The allocation of considerable resources in the Italian National Research Plan (PNR) brought about the formation of a CNR‐ENEA‐INFN‐University of Roma "Tor Vergata" study group. A conceptual design study has been developed and possible schemes for linac sources have been investigated, bringing to the SPARX proposal. We report in this paper the results of a preliminary start to end simulation concerning one option we are considering based on an S‐band normal conducting linac with high brightness photoinjector integrated in a RF compressor