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1.
Phys Rev Lett ; 126(7): 072501, 2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33666458

RESUMEN

We studied the proton-rich T_{z}=-1 nucleus ^{70}Kr through inelastic scattering at intermediate energies in order to extract the reduced transition probability, B(E2;0^{+}→2^{+}). Comparison with the other members of the A=70 isospin triplet, ^{70}Br and ^{70}Se, studied in the same experiment, shows a 3σ deviation from the expected linearity of the electromagnetic matrix elements as a function of T_{z}. At present, no established nuclear structure theory can describe this observed deviation quantitatively. This is the first violation of isospin symmetry at this level observed in the transition matrix elements. A heuristic approach may explain the anomaly by a shape change between the mirror nuclei ^{70}Kr and ^{70}Se contrary to the model predictions.

2.
Environ Res ; 192: 110291, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33027628

RESUMEN

Due to population growth, urbanization and economic development, demand for freshwater in urban areas is increasing throughout Europe. At the same time, climate change, eutrophication and pollution are affecting the availability of water supplies. Sicily, a big island in southern Italy, suffers from an increasing drought and consequently water shortage. In the last decades, in Sicilian freshwater reservoirs several Microcystis aeruginosa and more recently Planktothrix rubescens blooms were reported. The aims of the study were: (1) identify and quantify the occurring species of cyanobacteria (CB), (2) identify which parameters, among those investigated in the waters, could favor their growth, (3) set up a model to identify reservoirs that need continuous monitoring due to the presences, current or prospected, of cyanobacterial blooms and of microcystins, relevant for environmental and, consequentially, for human health. Fifteen artificial reservoirs among the large set of Sicilian artificial water bodies were selected and examined for physicochemical and microbiological characterization. Additional parameters were assessed, including the presence, identification and count of the cyanobacterial occurring species, the measurement of microcystins (MCs) levels and the search for the genes responsible for the toxins production. Principal Component Analysis (PCA) was used to relate environmental condition to cyanobacterial growth. Water quality was poor for very few parameters, suggesting common anthropic pressures, and PCA highlighted clusters of reservoirs vulnerable to hydrological conditions, related to semi-arid Mediterranean climate and to the use of the reservoir. In summer, bloom was detected in only one reservoir and different species was highlighted among the Cyanobacteria community. The only toxins detected were microcystins, although always well below the WHO reference value for drinking waters (1.0 µg/L). However, molecular analysis could not show the presence of potential cyanotoxins producers since a few numbers of cells among total could be sufficient to produce these low MCs levels but not enough high to be proved by the traditional molecular method applied. A simple environmental risk-based model, which accounts for the high variability of both cyanobacteria growth and cyanotoxins producing, is proposed as a cost-effective tool to evaluate the need for monitoring activities in reservoirs aimed to guarantee supplying waters safety.


Asunto(s)
Cianobacterias , Calidad del Agua , Monitoreo del Ambiente , Europa (Continente) , Eutrofización , Humanos , Microcistinas/análisis , Sicilia
3.
Phys Rev Lett ; 124(15): 152501, 2020 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-32357059

RESUMEN

The lifetimes of the first excited 2^{+} states in the N=Z nuclei ^{80}Zr, ^{78}Y, and ^{76}Sr have been measured using the γ-ray line shape method following population via nucleon-knockout reactions from intermediate-energy rare-isotope beams. The extracted reduced electromagnetic transition strengths yield new information on where the collectivity is maximized and provide evidence for a significant, and as yet unexplained, odd-odd vs even-even staggering in the observed values. The experimental results are analyzed in the context of state-of-the-art nuclear density-functional model calculations.

4.
Phys Rev Lett ; 124(6): 062502, 2020 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-32109128

RESUMEN

The nuclei below lead but with more than 126 neutrons are crucial to an understanding of the astrophysical r process in producing nuclei heavier than A∼190. Despite their importance, the structure and properties of these nuclei remain experimentally untested as they are difficult to produce in nuclear reactions with stable beams. In a first exploration of the shell structure of this region, neutron excitations in ^{207}Hg have been probed using the neutron-adding (d,p) reaction in inverse kinematics. The radioactive beam of ^{206}Hg was delivered to the new ISOLDE Solenoidal Spectrometer at an energy above the Coulomb barrier. The spectroscopy of ^{207}Hg marks a first step in improving our understanding of the relevant structural properties of nuclei involved in a key part of the path of the r process.

5.
Phys Rev Lett ; 124(6): 062501, 2020 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-32109090

RESUMEN

The low-lying energy spectrum of the extremely neutron-deficient self-conjugate (N=Z) nuclide _{44}^{88}Ru_{44} has been measured using the combination of the Advanced Gamma Tracking Array (AGATA) spectrometer, the NEDA and Neutron Wall neutron detector arrays, and the DIAMANT charged particle detector array. Excited states in ^{88}Ru were populated via the ^{54}Fe(^{36}Ar,2nγ)^{88}Ru^{*} fusion-evaporation reaction at the Grand Accélérateur National d'Ions Lourds (GANIL) accelerator complex. The observed γ-ray cascade is assigned to ^{88}Ru using clean prompt γ-γ-2-neutron coincidences in anticoincidence with the detection of charged particles, confirming and extending the previously assigned sequence of low-lying excited states. It is consistent with a moderately deformed rotating system exhibiting a band crossing at a rotational frequency that is significantly higher than standard theoretical predictions with isovector pairing, as well as observations in neighboring N>Z nuclides. The direct observation of such a "delayed" rotational alignment in a deformed N=Z nucleus is in agreement with theoretical predictions related to the presence of strong isoscalar neutron-proton pair correlations.

6.
Phys Rev Lett ; 124(4): 042503, 2020 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-32058764

RESUMEN

There is sparse direct experimental evidence that atomic nuclei can exhibit stable "pear" shapes arising from strong octupole correlations. In order to investigate the nature of octupole collectivity in radium isotopes, electric octupole (E3) matrix elements have been determined for transitions in ^{222,228}Ra nuclei using the method of sub-barrier, multistep Coulomb excitation. Beams of the radioactive radium isotopes were provided by the HIE-ISOLDE facility at CERN. The observed pattern of E3 matrix elements for different nuclear transitions is explained by describing ^{222}Ra as pear shaped with stable octupole deformation, while ^{228}Ra behaves like an octupole vibrator.

7.
Phys Rev Lett ; 121(19): 192502, 2018 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-30468583

RESUMEN

Lifetime measurements of excited states of the light N=52 isotones ^{88}Kr, ^{86}Se, and ^{84}Ge have been performed, using the recoil distance Doppler shift method and VAMOS and AGATA spectrometers for particle identification and gamma spectroscopy, respectively. The reduced electric quadrupole transition probabilities B(E2;2^{+}→0^{+}) and B(E2;4^{+}→2^{+}) were obtained for the first time for the hard-to-reach ^{84}Ge. While the B(E2;2^{+}→0^{+}) values of ^{88}Kr, ^{86}Se saturate the maximum quadrupole collectivity offered by the natural valence (3s, 2d, 1g_{7/2}, 1h_{11/2}) space of an inert ^{78}Ni core, the value obtained for ^{84}Ge largely exceeds it, suggesting that shape coexistence phenomena, previously reported at N≲49, extend beyond N=50. The onset of collectivity at Z=32 is understood as due to a pseudo-SU(3) organization of the proton single-particle sequence reflecting a clear manifestation of pseudospin symmetry. It is realized that the latter provides actually reliable guidance for understanding the observed proton and neutron single particle structure in the whole medium-mass region, from Ni to Sn, pointing towards the important role of the isovector-vector ρ field in shell-structure evolution.

8.
Curr Cardiol Rep ; 20(10): 83, 2018 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-30105555

RESUMEN

PURPOSE OF REVIEW: This review aims to summarize the current knowledge on the genetic background of dilated cardiomyopathy (DCM), with particular attention to the genotype-phenotype correlations and the possible implications for clinical management. RECENT FINDINGS: Next generation sequencing (NGS) has led to the identification of an increasing number of genes and mutations responsible for DCM. This genetic variability is probably related to the extreme heterogeneity of disease manifestation. Important findings have associated mutations of Lamin A/C (LMNA) and Filamin C (FLNC) to poor prognosis and the propensity to cause an arrhythmic phenotype, respectively. However, a deeper understanding of the genotype-phenotype correlation is necessary, because it could have several implications for the clinical management of the patients. Furthermore, the correct interpretation of pathogenicity of mutations and the clinical impact of genetic testing in DCM patients still represent important fields to be implemented. A pathogenic gene mutation can be identified in almost 40% of DCM patients. The recent discoveries and future research in the field of genotype-phenotype correlation may lead to a more personalized management of the mutation carriers towards the application of precision medicine in DCM.


Asunto(s)
Cardiomiopatía Dilatada/genética , Mutación , Arritmias Cardíacas/genética , Arritmias Cardíacas/mortalidad , Cardiomiopatía Dilatada/cirugía , Muerte Súbita Cardíaca/etiología , Estudios de Asociación Genética , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Pronóstico , Medición de Riesgo , Factores de Riesgo
9.
Phys Rev Lett ; 118(16): 162501, 2017 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-28474951

RESUMEN

Prompt γ-ray spectroscopy of the neutron-rich ^{96}Kr, produced in transfer- and fusion-induced fission reactions, has been performed using the combination of the Advanced Gamma Tracking Array and the VAMOS++ spectrometer. A second excited state, assigned to J^{π}=4^{+}, is observed for the first time, and a previously reported level energy of the first 2^{+} excited state is confirmed. The measured energy ratio R_{4/2}=E(4^{+})/E(2^{+})=2.12(1) indicates that this nucleus does not show a well-developed collectivity contrary to that seen in heavier N=60 isotones. This new measurement highlights an abrupt transition of the degree of collectivity as a function of the proton number at Z=36, of similar amplitude to that observed at N=60 at higher Z values. A possible reason for this abrupt transition could be related to the insufficient proton excitations in the g_{9/2}, d_{5/2}, and s_{1/2} orbitals to generate strong quadrupole correlations or to the coexistence of competing different shapes. An unexpected continuous decrease of R_{4/2} as a function of the neutron number up to N=60 is also evidenced. This measurement establishes the Kr isotopic chain as the low-Z boundary of the island of deformation for N=60 isotones. A comparison with available theoretical predictions using different beyond mean-field approaches shows that these models fail to reproduce the abrupt transitions at N=60 and Z=36.

10.
Phys Rev Lett ; 118(24): 242502, 2017 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-28665637

RESUMEN

The level structure of the neutron-rich ^{77}Cu nucleus is investigated through ß-delayed γ-ray spectroscopy at the Radioactive Isotope Beam Factory of the RIKEN Nishina Center. Ions of ^{77}Ni are produced by in-flight fission, separated and identified in the BigRIPS fragment separator, and implanted in the WAS3ABi silicon detector array, surrounded by Ge cluster detectors of the EURICA array. A large number of excited states in ^{77}Cu are identified for the first time by correlating γ rays with the ß decay of ^{77}Ni, and a level scheme is constructed by utilizing their coincidence relationships. The good agreement between large-scale Monte Carlo shell model calculations and experimental results allows for the evaluation of the single-particle structure near ^{78}Ni and suggests a single-particle nature for both the 5/2_{1}^{-} and 3/2_{1}^{-} states in ^{77}Cu, leading to doubly magic ^{78}Ni.

11.
Nature ; 469(7328): 68-71, 2011 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-21179086

RESUMEN

Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing, in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus (92)Pd. Gamma rays emitted following the (58)Ni((36)Ar,2n)(92)Pd fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution γ-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction. We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.

12.
J Eur Acad Dermatol Venereol ; 31(12): 2119-2123, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28449275

RESUMEN

INTRODUCTION: The public perception of dermatology and dermatologists may be very relevant in guiding strategies for improving dermatologic care but it has been poorly investigated in Europe. OBJECTIVE: To investigate the public's perception of dermatology and dermatologists in Italy. METHODS: A representative sampling of Italian adults (n = 1500, aged 18-70 years), residing throughout the national territory was interviewed through a population-based telephone survey using a structured questionnaire. RESULTS: The majority of interviewed aged between 35 and 54 years (45%) and had an intermediate educational level (57%), were employed (56%), and had at least one child in the family (68%). 70% of the interviewed knew at least one skin disease, particularly psoriasis, dermatitis, urticaria, skin tumours and nevi. The general practitioner resulted to be the first healthcare provider to consult in the case of skin problems for 73% of surveyed, with only 27% referring directly the private dermatologist. The dermatologist was the main referral specialist for psoriasis, pruritus and skin tumours by 66%, 54% and 53% of the sample, respectively. The most common reason for dermatological consultation was the control of nevi. In the case of childhood dermatitis, 52% indicated the paediatrician and 38% the dermatologist as the reference specialist. Almost half of the surveyed turned out to have a trusted dermatologist to consult in the case of skin problems. Finally, among those visited at least one time by a dermatologist, 46% were promoters, that is, they would recommend their dermatologist to a friend (net promoter score, 27). CONCLUSIONS: The general population has a wide-ranging understanding of skin diseases and the central role of dermatologists in skin care. Patients are looking for technical competence and loyalty, because this lead to more trusted and satisfactory physician-patient relationship. Public campaigns may be relevant in increasing awareness on curability of common skin diseases.


Asunto(s)
Dermatólogos , Dermatología , Opinión Pública , Enfermedades de la Piel , Adolescente , Adulto , Anciano , Femenino , Humanos , Italia , Masculino , Persona de Mediana Edad , Autoinforme , Adulto Joven
13.
J Clin Microbiol ; 54(3): 576-84, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26677254

RESUMEN

Despite the current reliance on blood cultures (BCs), the diagnosis of bloodstream infections (BSIs) can be sped up using new technologies performed directly on positive BC bottles. Two methods (the MALDI BioTyper system and FilmArray blood culture identification [BCID] panel) are potentially applicable. In this study, we performed a large-scale clinical evaluation (1,585 microorganisms from 1,394 BSI episodes) on the combined use of the MALDI BioTyper and FilmArray BCID panel compared to a reference (culture-based) method. As a result, the causative organisms of 97.7% (1,362/1,394) of the BSIs were correctly identified by our MALDI BioTyper and FilmArray BCID-based algorithm. Specifically, 65 (5.3%) out of 1,223 monomicrobial BCs that provided incorrect or invalid identifications with the MALDI BioTyper were accurately detected by the FilmArray BCID panel; additionally, 153 (89.5%) out of 171 polymicrobial BCs achieved complete identification with the FilmArray BCID panel. Conversely, full use of the MALDI BioTyper would have resulted in the identification of only 1 causative organism in 97/171 (56.7%) of the polymicrobial cultures. By applying our diagnostic algorithm, the median time to identification was shortened (19.5 h versus 41.7 h with the reference method; P < 0.001), and the minimized use of the FilmArray BCID panel led to a significant cost savings. Twenty-six out of 31 microorganisms that could not be identified were species/genera not designed to be detected with the FilmArray BCID panel, indicating that subculture was not dispensable for a few of our BSI episodes. In summary, the fast and effective testing of BC bottles is realistically adoptable in the clinical microbiology laboratory workflow, although the usefulness of this testing for the management of BSIs remains to be established.


Asunto(s)
Sangre/microbiología , Técnicas Microbiológicas/métodos , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena de la Polimerasa/métodos , Sepsis/diagnóstico , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Algoritmos , Humanos , Técnicas Microbiológicas/economía , Técnicas de Diagnóstico Molecular/economía , Estudios Prospectivos , Sensibilidad y Especificidad , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/economía , Factores de Tiempo
14.
Opt Express ; 24(26): 29984-29993, 2016 Dec 26.
Artículo en Inglés | MEDLINE | ID: mdl-28059383

RESUMEN

We report for the first time and characterize experimentally the complex optical conductivity of graphene on silicon photonic waveguides. This permits us to predict accurately the behavior of photonic integrated devices encompassing graphene layers. Exploiting a Si microring add/drop resonator, we show the effect of electrical gating of graphene on the complex effective index of the waveguide by measuring both the wavelength shift of the resonance and the change in the drop peak transmission. Due to electro-refractive effect of graphene a giant (>10-3) change in the effective index is demonstrated for the first time on Si photonics waveguides and this large effect will crucially impact performances and consumption of Si photonics devices. We confirmed the results by two independent experiments involving two different gating schemes: Si gating through the ridge waveguide, and polymer-electrolyte gating. Both the experiments demonstrate a very large phase effect in good agreement with numerical calculations. The reported results validate the Kubo model for the case of graphene-Si photonics interfaces and for propagation in this type of waveguide. This is fundamental for the next design and fabrication of future graphene-silicon photonics devices.

15.
Opt Lett ; 41(24): 5656-5659, 2016 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-27973482

RESUMEN

A circuit for the management of any arbitrary polarization state of light is demonstrated on an integrated silicon (Si) photonics platform. This circuit allows us to adapt any polarization into the standard fundamental TE mode of a Si waveguide and, conversely, to control the polarization and set it to any arbitrary polarization state. In addition, the integrated thermal tuning allows kilohertz speed which can be used to perform a polarization scrambler. The circuit was used in a WDM link and successfully used to adapt four channels into a standard Si photonic integrated circuit.

16.
Phys Rev Lett ; 117(16): 162501, 2016 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-27792367

RESUMEN

In an experiment with the BigRIPS separator at the RIKEN Nishina Center, we observed two-proton (2p) emission from ^{67}Kr. At the same time, no evidence for 2p emission of ^{59}Ge and ^{63}Se, two other potential candidates for this exotic radioactivity, could be observed. This observation is in line with Q value predictions which pointed to ^{67}Kr as being the best new candidate among the three for two-proton radioactivity. ^{67}Kr is only the fourth 2p ground-state emitter to be observed with a half-life of the order of a few milliseconds. The decay energy was determined to be 1690(17) keV, the 2p emission branching ratio is 37(14)%, and the half-life of ^{67}Kr is 7.4(30) ms.

17.
Phys Rev Lett ; 117(22): 222302, 2016 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-27925748

RESUMEN

The ^{54}Fe nucleus was populated from a ^{56}Fe beam impinging on a Be target with an energy of E/A=500 MeV. The internal decay via γ-ray emission of the 10^{+} metastable state was observed. As the structure of this isomeric state has to involve at least four unpaired nucleons, it cannot be populated in a simple two-neutron removal reaction from the ^{56}Fe ground state. The isomeric state was produced in the low-momentum (-energy) tail of the parallel momentum (energy) distribution of ^{54}Fe, suggesting that it was populated via the decay of the Δ^{0} resonance into a proton. This process allows the population of four-nucleon states, such as the observed isomer. Therefore, it is concluded that the observation of this 10^{+} metastable state in ^{54}Fe is a consequence of the quark structure of the nucleons.

18.
Phys Rev Lett ; 117(6): 062501, 2016 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-27541463

RESUMEN

Shape parameters of a weakly deformed ground-state band and highly deformed slightly triaxial sideband in ^{42}Ca were determined from E2 matrix elements measured in the first low-energy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new state-of-the-art large-scale shell model and beyond-mean-field calculations. Experimental evidence for superdeformation of the band built on 0_{2}^{+} has been obtained and the role of triaxiality in the A∼40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time.

19.
Opt Express ; 23(22): 28163-9, 2015 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-26561087

RESUMEN

We report on a novel near infrared SiGe phototransistor fabricated by a standard silicon photonics foundry. The device is first investigated by simulations. The fabricated devices are characterized in terms of current-voltage characteristics at different optical power. Typical phototransistors exhibit 1.55µm record responsivity at low optical power exceeding 232A/W and 42A/W at 5V and 1V bias, respectively. A differential detection scheme is also proposed for the dark current cancellation to significantly increase the device sensitivity.

20.
Infection ; 43(6): 629-37, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26096951

RESUMEN

INTRODUCTION: Recent age-projection showed that the number of elderly is expected to rise significantly over the next decades worldwide. Accordingly, the prevalence of chronic and degenerative diseases will increase, among them osteoarthritis, resulting in more and older patients undergoing total joint arthroplasty and thereby also being at risk for associated complications. Among those, prosthetic joint infections are feared as threatening complication with a mortality approaching 8 % and causing long-term antibiotic therapy, immobilization and often account for operative revision. MATERIALS AND METHODS: This review summarizes epidemiological, microbiological, and therapeutic aspects of prosthetic joint infection in the elderly population. CONCLUSION: Considering the increase in the number of PJIs in the forthcoming years in most countries, a common action to reduce the associated morbidity and mortality is strongly encouraged in Europe.


Asunto(s)
Osteoartritis/epidemiología , Infecciones Relacionadas con Prótesis/epidemiología , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Europa (Continente)/epidemiología , Humanos , Incidencia , Osteoartritis/microbiología , Osteoartritis/terapia , Infecciones Relacionadas con Prótesis/microbiología , Infecciones Relacionadas con Prótesis/terapia , Análisis de Supervivencia
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