Isospin Dynamics in Heavy Ion Collisions: from Coulomb Barrier to Quark Gluon Plasma

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this report we present a selection of new reaction observables in dissipative collisions particularly sensitive to the symmetry term of the nuclear Equation of State (Iso-EoS). We will first discuss the Isospin Equilibration Dynamics. At low energies this manifests via the recently observed Dynamical Dipole Radiation, due to a collective neutron-proton oscillation with the symmetry term acting as a restoring force. At higher beam energies Iso-EoS effects will be seen in Imbalance Ratio Measurements, in particular from the correlations with the total kinetic energy loss. For fragmentation reactions in central events we suggest to look at the coupling between isospin distillation and radial flow. In Neck Fragmentation reactions important $Iso-EoS$ information can be obtained from the correlation between isospin content and alignement. The high density symmetry term can be probed from isospin effects on heavy ion reactions at relativistic energies (few AGeV range). Rather isospin sensitive observables are proposed from nucleon/cluster emissions, collective flows and meson production. The possibility to shed light on the controversial neutron/proton effective mass splitting in asymmetric matter is also suggested. A large symmetry repulsion at high baryon density will also lead to an "earlier" hadron-deconfinement transition in n-rich matter. A suitable treatment of the isovector interaction in the partonic EoS appears very relevant.Comment: 18 pages, 12 figures, lecture at the 2008 Erice School on Nuclear Physics, to appear in Progress in Particle and Nuclear Physic

Phase transitions of hadronic to quark matter at finite T and \mu_B

The phase transition of hadronic to quark matter and the boundaries of the mixed hadron-quark coexistence phase are studied within the two Equation of State (EoS) model. The relativistic effective mean field approach with constant and density dependent meson-nucleon couplings is used to describe hadronic matter, and the MIT Bag model is adopted to describe quark matter. The boundaries of the mixed phase for different Bag constants are obtained solving the Gibbs equations. We notice that the dependence on the Bag parameter of the critical temperatures (at zero chemical potential) can be well reproduced by a fermion ultrarelativistic quark gas model, without contribution from the hadron part. At variance the critical chemical potentials (at zero temperature) are very sensitive to the EoS of the hadron sector. Hence the study of the hadronic EoS is much more relevant for the determination of the transition to the quark-gluon-plasma at finite baryon density and low-T. Moreover in the low temperature and finite chemical potential region no solutions of the Gibbs conditions are existing for small Bag constant values, B < (135 MeV)^4. Isospin effects in asymmetric matter appear relevant in the high chemical potential regions at lower temperatures, of interest for the inner core properties of neutron stars and for heavy ion collisions at intermediate energies.Comment: 24 pages and 16 figures (revtex4

Isospin dependence of relative yields of K+K^+ and K0K^0 mesons at 1.528 AGeV

Results on $K^+$ and $K^0$ meson production in $^{96}_{44}$Ru + $^{96}_{44}$Ru and $^{96}_{40}$Zr + $^{96}_{40}$Zr collisions at a beam kinetic energy of 1.528$A$ GeV, measured with the FOPI detector at GSI-Darmstadt, are investigated as a possible probe of isospin effects in high density nuclear matter. The measured double ratio ($K^+/K^0$)$_{Ru}$/($K^+/K^0$)$_{Zr}$ is compared to the predictions of a thermal model and a Relativistic Mean Field transport model using two different collision scenarios and under different assumptions on the stiffness of the symmetry energy. We find a good agreement with the thermal model prediction and the assumption of a soft symmetry energy for infinite nuclear matter while more realistic transport simulations of the collisions show a similar agreement with the data but also exhibit a reduced sensitivity to the symmetry term.Comment: 5 pages, 3 figures. accepted for publication in Phys. Rev.

A Novel Radiotherapeutic Approach to Treat Bulky Metastases Even From Cutaneous Squamous Cell Carcinoma: Its Rationale and a Look at the Reliability of the Linear-Quadratic Model to Explain Its Radiobiological Effects

Introduction: Metastatic cutaneous squamous cell carcinoma (cSCC) is a very rare condition. The lack of definition of an oligometastatic subgroup means that there is no consensus for its treatment, unlike the mucosal head and neck counterpart. Like the latter, the cutaneous form is able to develop bulky tumor masses. When this happens, the classic care approach is just for palliative intent due to a likely unfavorable benefit–risk balance typical of aggressive treatments. Here we proposed a novel radiotherapy (RT) technique to treat bulky metastases from cSCC in the context of an overall limited tumor burden and tried to explain its clinical outcome by the currently available mathematical radiobiological and ad hoc developed models. Methods: We treated a case of facial cSCC with three metastases: two of them by classic stereotactic RT and the other by lattice RT supported by metabolic imaging (18F-FDG PET) due to its excessively large dimensions. For the latter lesion, we compared four treatment plans with different RT techniques in order to define the best approach in terms of normal tissue complication probability (NTCP) and tumor control probability (TCP). Moreover, we developed an ad hoc mathematical radiobiological model that could fit better with the characteristics of heterogeneity of this bulky metastasis for which, indeed, a segmentation of normoxic, hypoxic, and necrotic subvolumes might have been&nbsp;assumed. Results: We observed a clinical complete response in all three disease sites; the bulky metastasis actually regressed more rapidly than the other two treated by stereotactic RT. For the large lesion, NTCP predictions were good for all four different plans but even significantly better for the lattice RT plan. Neither the classic TCP nor the ad hoc developed radiobiological models could be totally adequate to explain the reported outcome. This finding might support a key role of the host immune system. Conclusions: PET-guided lattice RT might be safe and effective for the treatment of bulky lesions from cSCC. There might be some need for complex mathematical radiobiological models that are able to take into account any immune system’s role in order to explain the possible mechanisms of the tumor response to radiation and the relevant key points to enhance it

Craniofacial modifications in children with habitual snoring and obstructive sleep apnoea: A case-control study

Habitual snoring and obstructive sleep apnoea in children, which are frequently associated with adenotonsillar hypertrophy, may begin early in life and in relation with orocraniofacial features. The aim of this study was to detect the presence of early bone craniofacial modifications in young children with along history of habitual snoring. Twenty-six habitually snoring children (mean age 4.6 yrs) were studied by nocturnal portable recording or diurnal polysomnography, cephalometry and orthodontic evaluation. A comparison of cephalometric findings was made between the studied group and 26 age-matched children (mean age 5.1 yrs) with no history of snoring or respiratory problems during sleep. The cephalometric analyses showed a significant increase in craniomandibular intermaxillar, lower and upper goniac angles with a retroposition and posterior rotation of the mandible (high angle face) and a reduction in the rhinopharynx space caused by higher thickness of adenoids in habitually snoring children compared with controls. Cross-bites and labial incompetence as well as daytime symptoms and familiarity for habitual snoring were found in most of the studied group of snorers compared with controls. The results indicate that upper airway obstruction during sleep is associated with mild but significant cephalometric and craniofacial modifications in children complaining of habitual snoring. Whether this skeletal conformation is genetically determined or influenced by the early onset of habitual snoring remains to be assessed

Neuropsychological changes in isolated REM sleep behavior disorder: A systematic review and meta-analysis of cross-sectional and longitudinal studies

The aim of this meta-analysis is twofold: (a) to assess cognitive impairments in isolated rapid eye movement (REM) sleep behavior disorder (iRBD) patients compared to healthy controls (HC); (b) to quantitatively estimate the risk of developing a neurodegenerative disease in iRBD patients according to baseline cognitive assessment. To address the first aim, cross-sectional studies including polysomnography-confirmed iRBD patients, HC, and reporting neuropsychological testing were included. To address the second aim, longitudinal studies including polysomnography-confirmed iRBD patients, reporting baseline neuropsychological testing for converted and still isolated patients separately were included. The literature search was conducted based on PRISMA guidelines and the protocol was registered at PROSPERO (CRD42021253427). Cross-sectional and longitudinal studies were searched from PubMed, Web of Science, Scopus, and Embase databases. Publication bias and statistical heterogeneity were assessed respectively by funnel plot asymmetry and using I2. Finally, a random-effect model was performed to pool the included studies. 75 cross-sectional (2,398 HC and 2,460 iRBD patients) and 11 longitudinal (495 iRBD patients) studies were selected. Cross-sectional studies showed that iRBD patients performed significantly worse in cognitive screening scores (random-effects (RE) model = –0.69), memory (RE model = –0.64), and executive function (RE model = –0.50) domains compared to HC. The survival analyses conducted for longitudinal studies revealed that lower executive function and language performance, as well as the presence of mild cognitive impairment (MCI), at baseline were associated with an increased risk of conversion at follow-up. Our study underlines the importance of a comprehensive neuropsychological assessment in the context of iRBD

Assessing Sleep Habits in Italian Community-Dwelling Adolescents: Psychometric Properties of the School Sleep Habits Survey Scales

Background. In the field of adolescent sleep research, different sleep surveys have been implemented; however, psychometric properties of these instruments have been investigated only minimally. Methods. In order to assess the psychometric properties of the Sleep-Wake Problems Behaviour Scale (SWP), the Sleepiness Scale (SLS), and the Morningness/Eveningness Questionnaire (ME), a moderately large sample of community-dwelling Italian adolescents (N = 778; 59.8% female; mean age = 15.77 years) was administered the Italian translation of the School Sleep Habits Survey. Results. Internal consistency estimates values were satisfactory for all measures; dimensionality analyses suggested a unidimensional structure for SWP, SLS and ME, respectively. Goodness-of-fit statistics for the one-factor model of the SLS, SWP, and ME scale items were adequate for all measures. Non -redundant taxometric analysis results consistently suggested a dimensional latent structure for the SLS, SWP, and ME, respectively. Conclusion. Our findings supported the use of the SLS, SWP, and ME total scores as measures of sleepiness, sleep-wake problem, and morningness/eveningness, at least among Italian community -dwelling adolescents, and encourage practitioners to rely on the conventional percentiles in order to interpret the SLS, SWP, and ME total scores

Continuous positive airway pressure (CPAP) in nonapneic asthma: A clinical review of current evidence

© 2020 by Turkish Thoracic Society-. The use of continuous positive airway pressure (CPAP) in asthma has been a point of debate over the past several years. Various studies, including those on animals and humans have attempted to understand the role and pathophysiology of CPAP in patients with either well controlled or poorly controlled asthma. The aim of this manuscript is to review the currently available literature on the physiologic and clinical effects of CPAP in animal models of asthma and on humans with stable asthma

Migraine and restless legs syndrome: is there an association?

Occasional clinical reports have suggested a link between migraine and restless legs syndrome. We undertook a systematic review of the evidence, which supports this association, and consider possible shared pathogenic mechanisms and the implications for current clinical practice

Persistence of the effects of the covid-19 lockdown on sleep: A longitudinal study

The effects of the COVID-19 pandemic on sleep have been widely documented, but longitudinal evaluations during different phases of the "COVID-19 era" are needed to disentangle the specific consequences of the r145estrictive measures on sleep variables. The aim of this study was to assess the immediate effect of the lockdown's end on sleep and sleep-related dimensions in an Italian sample, also considering the stress and depressive symptoms. We used an online survey to longitudinally collect data on sociodemographic, environmental, clinical, sleep, and sleep-related variables in two time points: during and immediately after the lockdown. The final sample included 102 participants. The large prevalence of poor sleep quality, clinically relevant pre-sleep arousal, and depressive symptoms, as well as poor sleep quality and pre-sleep arousal score observed during the lockdown, remained stable after its end. On the other hand, the prevalence of moderate-to-severe event-related stress and intrusive symptom scores exhibited a drastic reduction after the end of home confinement. Both bedtime and rise time were anticipated after the lockdown, while sleep quality exhibited only a trend of post-lockdown sleep disturbance reduction. Our findings point to a reduced stress level (specific for the intrusive symptomatology) after the end of the lockdown and persistence of sleep problems, suggesting two non-mutually exclusive hypotheses: (a) the strict restrictive measures are not the main cause of sleep problems during the pandemic and (b) home confinement induces long-lasting effects on sleep observable after its end, and a longer period of time might be needed to observe an improvement