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1.
Nature ; 569(7754): 53-58, 2019 05.
Article in English | MEDLINE | ID: mdl-31043730

ABSTRACT

Nuclear magic numbers correspond to fully occupied energy shells of protons or neutrons inside atomic nuclei. Doubly magic nuclei, with magic numbers for both protons and neutrons, are spherical and extremely rare across the nuclear landscape. Although the sequence of magic numbers is well established for stable nuclei, experimental evidence has revealed modifications for nuclei with a large asymmetry between proton and neutron numbers. Here we provide a spectroscopic study of the doubly magic nucleus 78Ni, which contains fourteen neutrons more than the heaviest stable nickel isotope. We provide direct evidence of its doubly magic nature, which is also predicted by ab initio calculations based on chiral effective-field theory interactions and the quasi-particle random-phase approximation. Our results also indicate the breakdown of the neutron magic number 50 and proton magic number 28 beyond this stronghold, caused by a competing deformed structure. State-of-the-art phenomenological shell-model calculations reproduce this shape coexistence, predicting a rapid transition from spherical to deformed ground states, with 78Ni as the turning point.

2.
Phys Rev Lett ; 125(1): 012501, 2020 Jul 03.
Article in English | MEDLINE | ID: mdl-32678621

ABSTRACT

Twenty-one two-proton knockout (p,3p) cross sections were measured from neutron-rich nuclei at ∼250 MeV/nucleon in inverse kinematics. The angular distribution of the three emitted protons was determined for the first time, demonstrating that the (p,3p) kinematics are consistent with two sequential proton-proton collisions within the projectile nucleus. Ratios of (p,3p) over (p,2p) inclusive cross sections follow the trend of other many-nucleon removal reactions, further reinforcing the sequential nature of (p,3p) in neutron-rich nuclei.

3.
Phys Rev Lett ; 122(16): 162503, 2019 Apr 26.
Article in English | MEDLINE | ID: mdl-31075035

ABSTRACT

Fifty-five inclusive single nucleon-removal cross sections from medium mass neutron-rich nuclei impinging on a hydrogen target at ∼250 MeV/nucleon are measured at the RIKEN Radioactive Isotope Beam Factory. Systematically higher cross sections are found for proton removal from nuclei with an even number of protons as compared to odd-proton number projectiles for a given neutron separation energy. Neutron removal cross sections display no even-odd splitting, contrary to nuclear cascade model predictions. Both effects are understood through simple considerations of neutron separation energies and bound state level densities originating in pairing correlations in the daughter nuclei. These conclusions are supported by comparison with semimicroscopic model predictions, highlighting the enhanced role of low-lying level densities in nucleon-removal cross sections from loosely bound nuclei.

5.
Phys Rev Lett ; 119(19): 192501, 2017 Nov 10.
Article in English | MEDLINE | ID: mdl-29219515

ABSTRACT

In-beam γ-ray spectroscopy of ^{79}Cu is performed at the Radioactive Isotope Beam Factory of RIKEN. The nucleus of interest is produced through proton knockout from a ^{80}Zn beam at 270 MeV/nucleon. The level scheme up to 4.6 MeV is established for the first time and the results are compared to Monte Carlo shell-model calculations. We do not observe significant knockout feeding to the excited states below 2.2 MeV, which indicates that the Z=28 gap at N=50 remains large. The results show that the ^{79}Cu nucleus can be described in terms of a valence proton outside a ^{78}Ni core, implying the magic character of the latter.

6.
Phys Rev Lett ; 115(19): 192501, 2015 Nov 06.
Article in English | MEDLINE | ID: mdl-26588374

ABSTRACT

We report on the measurement of the first 2(+) and 4(+) states of (66)Cr and (70,72)Fe via in-beam γ-ray spectroscopy. The nuclei of interest were produced by (p,2p) reactions at incident energies of 260 MeV/nucleon. The experiment was performed at the Radioactive Isotope Beam Factory, RIKEN, using the DALI 2γ-ray detector array and the novel MINOS device, a thick liquid hydrogen target combined with a vertex tracker. A low-energy plateau of 2(1)(+) and 4(1)(+) energies as a function of the neutron number was observed for N≥38 and N≥40 for even-even Cr and Fe isotopes, respectively. State-of-the-art shell model calculations with a modified Lenzi-Nowacki-Poves-Sieja (LNPS) interaction in the pfg(9/2)d(5/2) valence space reproduce the observations. Interpretation within the shell model shows an extension of the island of inversion at N=40 for more neutron-rich isotopes towards N=50.

7.
Eur J Clin Microbiol Infect Dis ; 33(7): 1095-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24442608

ABSTRACT

Third-generation cephalosporins are used to treat inpatients with community-acquired pneumonia. Some of these prescriptions may be avoided, i.e. replaced by agents less likely to promote ESBL-mediated resistance. Our objectives were to assess the recent trend of third-generation cephalosporins use for pneumonia in the emergency department, and the proportion of avoidable prescriptions. This was a retrospective study of patients treated for community-acquired pneumonia in an emergency department, and subsequently hospitalized in non ICU wards. Third-generation cephalosporin prescriptions were presumed unavoidable if they met both criteria: (i) age ≥ 65 yr or comorbid condition, and (ii) allergy or intolerance to penicillin, or failure of penicillin first-line therapy, or treatment with penicillin in three previous months. Prescriptions were otherwise deemed avoidable. The proportion of patients treated with a third generation cephalosporin increased significantly from 13.9 % (6.9-24.1 %) in 2002 to 29.5 % (18.5-42.6 %) in 2012 (OR = 1.07 [1.01-1.14] , P = 0.02). This increase was independent from other factors associated with the prescription of a third-generation cephalosporin (immunocompromising condition, antibacterial therapy in three previous months, fluid resuscitation and REA-ICU class). Treatment with third-generation cephalosporin was avoidable in 118 out of 147 patients (80.3 % [72.7-86.2 %]). On day 7 after admission in the ED, treatment with third-generation cephalosporins was stopped or de-escalated in, respectively, 17 % and 32 % of patients. Antibiotic stewardship programs should be implemented to restrict the third-generation cephalosporins use for pneumonia in the emergency department.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Cephalosporins/therapeutic use , Community-Acquired Infections/drug therapy , Emergency Medical Services/methods , Emergency Service, Hospital , Pneumonia/drug therapy , Aged , Aged, 80 and over , Female , Humans , Male , Prohibitins , Retrospective Studies
8.
Mov Ecol ; 7: 29, 2019.
Article in English | MEDLINE | ID: mdl-31660153

ABSTRACT

BACKGROUND: The early life of marine apex predators is poorly known, particularly for diving species. The orientation and foraging skills are presumably less developed in juveniles than in adults, especially during their first year at sea when juveniles might disperse further than adults. METHODS: Over two years of monitoring, we tracked the movements of 17 juvenile king penguins (Aptenodytes patagonicus, ~ 1 year old) using satellite relay tags from Crozet Archipelago (Southern Indian Ocean), starting when birds left their natal colony for the first time. For comparison we also tagged 6 non-breeding adults, which at that stage, similar to juveniles, are unhampered by reproductive constraints and might roam further than breeders. We used a combination of cluster analysis and habitat modelling to investigate and compare the movement patterns and habitat use of experienced (non-breeding adults) and non-experienced (juveniles) individuals. RESULTS: While juvenile penguins and non-breeding adults followed similar routes, the movements by adults started later in the season and ranged over a considerably smaller area than juveniles. Net squared displacement analysis revealed that both groups did not move to a specific wintering area. Changes in direction of juveniles in respect to their departure island were similar and synchronous for both years. Habitat models revealed that foraging behaviour was affected by environmental variables such as wind or current speeds, sea surface temperature, or oceanic productivity, for both stages. Analysis of tracks revealed that birds moved predominately perpendicular or against the main direction of the Antarctic Circumpolar Current and the prevailing wind during austral summer (juveniles only) and autumn (juveniles and non-breeding adults). However, both juveniles and adults were more likely to move against the prevailing winds if productivity increased along their trajectories. CONCLUSIONS: The exceptional duration of our tracking study provided unprecedented insights into the distribution, habitat preferences and orientation of two poorly known life history stages of an expert avian diver. Our study suggests that juveniles might use both innate and learnt skills to reach profitable foraging areas during their first year at sea, which is critical in long-lived species.

9.
Ann Ig ; 18(2): 147-53, 2006.
Article in English | MEDLINE | ID: mdl-16649512

ABSTRACT

The aim of this survey was to evaluate the distribution of pathological gamblers treated in an alcohol or drug addiction treatment program run by the Italian National Health Service providing assistance to alcohol and drug abusers in Venice (North east Italy) from September 1 to December 31, 2001. Each drug- or alcohol-dependent patient retained for treatment for at least one month was administrated an anonymous precoded questionnaire to collect personal and socio-demographic features. The South Oaks Gambling Screen (SOGS) was used to measure pathological gambling and the Symptom Checklist-90-Revised (SCL-90-R) to measure psychological distress levels and psychiatric symptoms. Among the 113 enrolled subjects we found a greater prevalence of pathological gamblers among drug users than among alcoholics and drug abusers were younger than alcoholics; moreover, there was a prevalence of single status, low schooling, and a low-medium income despite full-time occupation. Only pathological gamblers revealed a significant positive correlation with a family history of gambling and reached positive scores (>1.5) for some likely psychiatric symptoms. Abuse disorders and pathological gambling are frequently associated with multidependence personality traits. Preventing substance abuse may reduce the pathological gambling rates and better results can be obtained with educational campaigns beginning earlier in life.


Subject(s)
Alcoholism/epidemiology , Gambling , Substance-Related Disorders/epidemiology , Adolescent , Adult , Age Factors , Aged , Alcoholism/psychology , Alcoholism/therapy , Data Collection , Data Interpretation, Statistical , Female , Gambling/psychology , Humans , Italy/epidemiology , Male , Middle Aged , Odds Ratio , Prevalence , Socioeconomic Factors , Substance-Related Disorders/prevention & control , Substance-Related Disorders/psychology , Substance-Related Disorders/therapy , Surveys and Questionnaires
10.
Ital J Neurol Sci ; 15(4): 177-82, 1994 May.
Article in English | MEDLINE | ID: mdl-7960670

ABSTRACT

A number of investigators have reported the detection of circulating autoantibodies directed against serum and cerebrospinal fluid (CSF) neuronal antigens in certain neurological clinical conditions. Using an immunohistochemical technique, we examined the sera and (when available) the CSF from 120 patients with several neurological disorders and 40 controls in order to analyze the incidence and specificity of the detection of these autoantibodies. Circulating autoantibodies were found in 3 patients with cerebellar degeneration and in 3 patients with stiff-man syndrome, and different staining patterns were revealed in the same disease. Our findings confirm the reported disease-specificity of the detection of these autoantibodies in biological fluids, suggesting that a standardized immunohistochemical technique could constitute an easy and reproducible diagnostic tool in selected neurological conditions. These procedures enable the identification of an immunological pathogenesis of the disease and, in some case, early cancer detection. When atypical staining patterns of staining are found at immunohistochemistry, Western blot characterization of the recognized neuronal antigens is recommended.


Subject(s)
Autoantibodies/immunology , Autoantigens/immunology , Cerebellum/immunology , Nervous System Diseases/immunology , Neurons/immunology , Aged , Animals , Autoantibodies/blood , Autoantibodies/cerebrospinal fluid , Autoimmune Diseases/blood , Autoimmune Diseases/cerebrospinal fluid , Autoimmune Diseases/immunology , Diabetes Mellitus, Type 1/immunology , Female , Humans , Immunoenzyme Techniques , Male , Middle Aged , Nervous System Diseases/blood , Nervous System Diseases/cerebrospinal fluid , Nervous System Diseases/diagnosis , Paraneoplastic Syndromes/blood , Paraneoplastic Syndromes/cerebrospinal fluid , Paraneoplastic Syndromes/diagnosis , Paraneoplastic Syndromes/immunology , Purkinje Cells/immunology , Rats , Rats, Sprague-Dawley
11.
Immunopharmacology ; 39(2): 157-64, 1998 May.
Article in English | MEDLINE | ID: mdl-9716262

ABSTRACT

Programmed cell death or apoptosis is a physiological cell suicide process that can be suppressed by survival factors. Monocytes undergo rapid apoptosis in culture, unless signalled by cytokines or the bacterial lipopolysaccharide LPS. We have investigated the effect on monocyte apoptosis of the immunostimulating agent RU 41740 (Biostim), a glycoprotein extract from the Klebsiella pneumoniae K2O1 strain that is used for the prevention of recurrent infections. RU 41740, as LPS, strongly enhanced monocyte survival in vitro, an effect related to apoptosis suppression. RU 41740 at concentration ranging from 1 ng/ml to 10 microg/ml prevented apoptosis induced both by survival factor deprival and by gamma-irradiation. Our observation suggests that enhancement of monocyte survival may represent a component of the reported immunostimulating effect of this compound.


Subject(s)
Adjuvants, Immunologic/pharmacology , Apoptosis/drug effects , Bacterial Proteins/pharmacology , Monocytes/drug effects , Cell Survival/drug effects , Cells, Cultured , Humans , Mitochondria/drug effects , Monocytes/physiology
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