High frequency acoustic modes in liquid gallium at the melting point

The microscopic dynamics in liquid gallium (l-Ga) at melting (T=315 K) has been studied by inelastic x-ray scattering. We demonstrate the existence of collective acoustic-like modes up to wave-vectors above one half of the first maximum of the static structure factor, at variance with earlier results from inelastic neutron scattering data [F.J. Bermejo et al. Phys. Rev. E 49, 3133 (1994)]. Despite the structural (an extremely rich polymorphism and rather complex phase diagram) and electronic (mixed valence) peculiarity of l-Ga, its collective dynamics is strikingly similar to the one of Van der Walls and alkali metals liquids. This result speaks in favor of the universality of the short time dynamics in monatomic liquids rather than of system-specific dynamics.Comment: LaTex format, 11 pages, 4 EncapsulatedPostScript figure

Total Widths And Slopes From Complex Regge Trajectories

Maximally complex Regge trajectories are introduced for which both Re $\alpha(s)$ and Im $\alpha(s)$ grow as $s^{1-\epsilon}$ ($\epsilon$ small and positive). Our expression reduces to the standard real linear form as the imaginary part (proportional to $\epsilon$) goes to zero. A scaling formula for the total widths emerges: $\Gamma_{TOT}/M\to$ constant for large M, in very good agreement with data for mesons and baryons. The unitarity corrections also enhance the space-like slopes from their time-like values, thereby resolving an old problem with the $\rho$ trajectory in $\pi N$ charge exchange. Finally, the unitarily enhanced intercept, $\alpha_{\rho}\approx 0.525$, \nolinebreak is in good accord with the Donnachie-Landshoff total cross section analysis.Comment: 9 pages, 3 Figure

Spatial and temporal hot spots of Aedes albopictus abundance inside and outside a South European metropolitan area

Aedes albopictus is a tropical invasive species which in the last decades spread worldwide, also colonizing temperate regions of Europe and US, where it has become a public health concern due to its ability to transmit exotic arboviruses, as well as severe nuisance problems due to its aggressive daytime outdoor biting behaviour. While several studies have been carried out in order to predict the potential limits of the species expansions based on eco-climatic parameters, few studies have so far focused on the specific effects of these variables in shaping its micro-geographic abundance and dynamics. The present study investigated eco-climatic factors affecting Ae. albopictus abundance and dynamics in metropolitan and sub-urban/rural sites in Rome (Italy), which was colonized in 1997 and is nowadays one of the most infested metropolitan areas in Southern Europe. To this aim, longitudinal adult monitoring was carried out along a 70 km-transect across and beyond the most urbanized and densely populated metropolitan area. Two fine scale spatiotemporal datasets (one with reference to a 20m circular buffer around sticky traps used to collect mosquitoes and the second to a 300m circular buffer within each sampling site) were exploited to analyze the effect of climatic and socio-environmental variables on Ae. albopictus abundance and dynamics along the transect. Results showed an association between highly anthropized habitats and high adult abundance both in metropolitan and sub-urban/ rural areas, with “small green islands” corresponding to hot spots of abundance in the metropolitan areas only, and a bimodal seasonal dynamics with a second peak of abundance in autumn, due to heavy rains occurring in the preceding weeks in association with permissive temperatures. The results provide useful indications to prioritize public mosquito control measures in temperate urban areas where nuisance, human-mosquito contact and risk of local arbovirus transmission are likely higher, and highlight potential public health risks also after the summer months typically associated with high mosquito densities

Hadronic Masses and Regge Trajectories

A comprehensive phenomenological analysis of experimental data and some theoretical models is presented here (for mesons) to critically discuss how Regge trajectory parameters depend on flavor. Through analytic continuation of physical trajectories (obtained from resonance data) into the space like region, we derive the suppression factor for heavy flavor production. The case of our D Regge exchange, both for D and $\Lambda_c$ production, is considered in some detail. Good agreement with data is reached confirming that indeed the slopes of heavier flavors decrease. This result suggests that the confinement potential has a substantial dependence on the quark masses. In a simple non-relativistic model, constrained to produce linear Regge trajectories, it is shown that a linear quark mass dependence is required (in the confinement part of the potential) in order for the slope to decrease in the appropriate way.Comment: 19 pages, 9 Figures, IV Table

Analysis of patients' needs after liver transplantation in Tuscany: a prevalence study.

BACKGROUND: The reorganization of the healthcare system in Tuscany aims at characterizing the hospitals as a place for the treatment of acute patients. This event, together with the improvement of long-term survival after orthotopic liver transplantation (OLT), calls for a management network able to ensure effective continuity of care for patient needs in the posttransplantation period. MATERIALS AND METHODS: An observational study of prevalence has been carried out with the primary objective to evaluate patients' needs and criticalities both in routine daily life and in urgency in the posttransplantation period and the capacity of the regional health system to support them. A survey, using a semi-structured questionnaire consisting of 27 questions, was administered to all patients resident in Tuscany who underwent transplantation from 2000 to 2010. The survey tool assessed the following: socio-demographic data, personal, family and social difficulties, problems emerged in the clinical routine and urgency, resolution modality, relationships with the general practitioner and the referral specialist, and services the patients would appreciate receiving in their province of residence. RESULTS: In the study, 346 patients matched the inclusion criteria of the study, 324 gave telephone consent to participate in the survey, and 225 responded (69.4%). The most frequent difficulties were as follows: depression (39.5%), difficulty in returning to work (29.3%), low income (22.6%), lack of self-sufficiency (22.6%), addictions (19.1%) (cigarette smoking 16.4%), 12.4% eating disorders, and 18.9% other difficulties (social isolation, absence of a family network, and so on). The main reasons for dissatisfaction were as follows: difficulty to obtain the required laboratory tests and lack of a reference structure at the local health facility. Few patients have a referral specialists in their area and most of them primarily refer to the Transplant Center even late after the procedure. DISCUSSION: Early diagnosis of specific conditions (depression, addiction, and eating disorders) should be implemented in the follow-up period and services such as counselling, dietary support, rehabilitation, and social services should be provided locally. An integrated management system between the transplantation center and the local facilities (hospitals, general practitioners, primary care, and laboratories) should be implemented and referral specialized centers should be identified locally

Perfusion machines and hepatocellular carcinoma: a good match between a marginal organ and an advanced disease?

Abstract Hepatocellular carcinoma (HCC) accounts for 90% of primary liver cancers, is the second leading cause of cancer-related deaths and the leading cause of death in patients with cirrhosis. Liver transplantation (LT) represents the ideal treatment for selected patients as it removes both the tumor and the underlying cirrhotic liver with 5-year survival rates higher than 70%. Unfortunately, due to tumor characteristics, patient co-morbidities or shortage of organs available for transplant, only 20% of patients can undergo curative treatment. Ex situ machine perfusion (MP) is a technology recently introduced that might potentially improve organ preservation, allow graft assessment and increase the pool of available organs. The purpose of this review is to provide an update on the current role of ex situ liver MP in liver transplantation for HCC patients

Corrosion behaviour of high temperature fuel cells: Issues for materials selection

The corrosion of alloy components in fuel cell is recurring issue and currently it has been leading to low performances of fuel cell and failures. This issue is more prominent in high temperature systems such as molten carbonate and solid oxide fuel cell which operate above 600 °C. The cathode side and anode side corrosion issues have been addressed by many groups but components like current collectors have not. In this framework materials selection is a key issue. Comparing different experiments it can be concluded that the choice of stainless steel (SS) is good choice. In particular, SS316L is good choice but long term test show high degradation of the components. This degradation is mainly due to migration (diffusion) of elements in oxide layer and in base material. Therefore, further studies are needed in order to deeply analyze such behavior. It will allow to better alloy compositions aimed to mitigate degradation and to design alloys showing stable performance of fuel cell

The occurrence of postoperative vertigo after CI

Background. The incidence of postoperative vertigo after cochlear implantation (CI) varies a lot in the literature. The aim of this work was to investigate both subjective complaints of vertigo before and after cochlear implantation and related it to to the preoperative vestibular function, the surgical procedure and to the position of CI at the postoperative neuroradiological study. Methods. Retrospective cohort study of adult CI series operated by the same surgeon (DZ) over the last 3 years. (N= 107). Sixty-six subjects (38 F; 28 M), aged from 21 to 78 years old were included in the study, lasting 83 CI. The outcomes of the pre-operative vestibular assessment were extracted from the database of the Vestibular Disorders Unit of the tertiary referral University Hospital of Milano from 1992 to 2018 (N=557). Post-operative presence/absence of vestibular disorders was analyzed and related to the preoperative vestibular examination and to the flat-panel computed tomography (FPCT) findings. Results: The patients were divided by age and by the presence of vestibular response of the operated ear measured by videoculography, caloric testing and video-impulse test. Sensorial analysis by static posturography was also included. The incidence of postoperative vertigo was higher in patients > 65 years old (36.3% vs 20.4%, p=0.03). Postoperative vertigo did not result related to the surgical procedure. The results are discussed with the review of the literature. Conclusion: Our results confirm the importance of vestibular testing in CI recipients, in order to better counsel the patient on the foreseeable post-operative course and to identify those patients who will need a vestibular rehabilitation

Abnormal hyperventilation in patients with hepatic cirrhosis: Role of enhanced chemosensitivity to carbon dioxide

BACKGROUND: Patients with hepatic cirrhosis frequently show idiopathic hyperventilation at rest, despite no concomitant cardiopulmonary disease. The aim of the study was to determine whether altered chemosensitivity either to hypoxia or hypercapnia could underlie inappropriate hyperventilation in cirrhotic patients. METHODS: We consecutively recruited 30 biopsy proven cirrhotic patients equally distributed in the three Child's classes A, B and C (age 54±8years, mean±SD). All patients underwent evaluation of chemosensitivity to hypoxia and to hypercapnia and blood sampling for brain natriuretic peptide, norepinephrine and progesterone, besides full clinical characterization. We also recruited 10 age- and gender-matched healthy controls (age 55±7years). RESULTS: Overall, 18 patients (60%) showed an increased chemosensitivity to carbon dioxide (CO(2)), while 8 patients (27%) showed enhanced chemosensitivity to hypoxia. Child's class C patients had lower arterial partial pressure of CO(2) (PaCO(2)), higher rest ventilation, increased chemosensitivity to hypercapnia, plasma level of norepinephrine and serum progesterone levels when compared to class A patients and controls (all p<0.05). Rest ventilation was positively related to pH (R=0.41, p=0.023), chemosensitivity to hypercapnia (R=0.54, p=0.002), and progesterone (R=0.53, p=0.016) and negatively to PaCO(2) (R=0.61, p<0.001), but not to hemoglobin level and chemosensitivity to hypoxia. Chemosensitivity to hypercapnia was positively related to PaCO(2) (R=0.74, p<0.001), serum progesterone (R=0.50, p=0.016), and to plasma norepinephrine (R=0.57, p=0.004). CONCLUSIONS: Enhanced chemosensitivity to hypercapnia was found in more decompensated cirrhotic patients and was associated with sympathetic overactivity and elevated serum progesterone, likely representing a key mechanism underlying the "unexplained" hyperventilation observed in such patients