Can antiferromagnetism and superconductivity coexist in the high-field paramagnetic superconductor Nd(O,F)FeAs?

We present measurements of the temperature and field dependencies of the magnetization M(T,H) of Nd(O0.89F0.11)FeAs at fields up to 33T, which show that superconductivity with the critical temperature Tc ~ 51K cannot coexist with antiferromagnetic ordering. Although M(T,H) at 55 < T < 140K exhibits a clear Curie-Weiss temperature dependence corresponding to the Neel temperature TN ~ 11-12K, the behavior of M(T,H) below Tc is only consistent with either paramagnetism of weakly interacting magnetic moments or a spin glass state. We suggest that the anomalous magnetic behavior of an unusual high-field paramagnetic superconductor Nd(O1-xFx)FeAs is mostly determined by the magnetic Nd ions.Comment: 4 pages, 4 figure

Microwave surface resistance of pristine and neutron-irradiated MgB2 samples in magnetic field

We report on the microwave surface resistance of two polycrystalline Mg11B2 samples; one consists of pristine material, the other has been irradiated at very high neutron fluence. It has already been reported that in the strongly irradiated sample the two gaps merge into a single value. The mw surface resistance has been measured in the linear regime as a function of the temperature and the DC magnetic field, at increasing and decreasing fields. The results obtained in the strongly irradiated sample are quite well justified in the framework of a generalized Coffey and Clem model, in which we take into account the field distribution inside the sample due to the critical state. The results obtained in the pristine sample show several anomalies, especially at low temperatures, which cannot be justified in the framework of standard models for the fluxon dynamics. Only at temperatures near Tc and for magnetic fields greater than 0.5Hc2(T) the experimental data can quantitatively be accounted for by the Coffey and Clem model, provided that the upper-critical-field anisotropy is taken into due account.Comment: RevTeX, 13 pages with 10 eps figures, in press on EPJ

Effectiveness of omalizumab in a patient with severe asthma and atopic dermatitis

The anti-IgE antibody omalizumab is currently indicated in severe asthma not controlled by standard drug therapy. Recently, new indications for omalizumab were suggested, which include atopic dermatitis (AD), a skin disorder characterized by elevated levels of IgE. We report the case of a 39-year old woman with severe asthma and severe AD, both resistant to conventional drug treatment. The patient had a IgE level of 1304 kU/L, which exceeded the recommended maximum level for treating asthma with omalizumab (stated in 700 Ku/L) but was far lower than previously reported in cases of AD treated with anti-IgE. The treatment consisted of a dose of omalizumab 375 mg every two weeks, and induced a rapid improvement of asthma, with no need of other drugs after three months, along with a progressive decline of severity of AD, which after five months was completely cured. These findings suggest the usefulness of omalizumab in patients with concomitant severe asthma and AD, also considering the pharmaco-economic balance obtained by withdrawing the multiple drugs used to treat both diseases

Enhanced flux pinning in neutron irradiated MgB2

We study the effect of neutron irradiation on the critical current density Jc of isotopically pure polycrystalline Mg11B2 samples. For fluences in the range 1017-1018 cm-2, Jc is enhanced and its dependence on magnetic field is significantly improved: we demonstrate that, in this regime, point-like pinning centers are effectively introduced in the system proportionally to the neutron fluence. Instead, for larger fluences, a strong suppression of the critical temperature accompanied by a decrease of both the upper critical field Bc2 and Jc is found.Comment: 13 pages, 3 igure

Neutron Irradiation of Mg11B2 : From the Enhancement to the Suppression of Superconducting Properties

In this letter we present the effect of neutron irradiation up to fluences of 3.9 1019 n/cm2 on the superconducting properties of MgB2. In order to obtain a disorder structure homogeneously distributed, the experiment was carried out on bulk samples prepared with the 11B isotope. Up to fluences of 1018 n/cm2 the critical temperature is slightly diminished (36 K) and the superconducting properties are significantly improved; the upper critical field is increased from 13.5 T to 20.3 T at 12 K and the irreversibility field is doubled at 5 K. For larger neutron fluences the critical temperature is suppressed down to 12 K and the superconducting properties come out strongly degraded.Comment: 13 pages, 4 figures. Submitted to Appl.Phys.Let

SiLiBA: Building the geological chert lithotheque

Lithotheques collect and exhibit raw material used by human communities for the manufacturing of objects during the Prehistory and represents an important tool of their knowledge. These collections are essential in the procuring and provenance study of archaeological lithic industries. This paper aims, firstly, to introduce SiLiBA, the lithotheque of the Earth and Geoenvironmental Sciences Department of the University of Bari Aldo Moro (Italy), as reference collection in the archaeological field studies, and secondly to propose guidelines and rules to build a lithotheque. The collection consists of about 900 pieces of geological cherts, which are the result of an expanded collecting action of primary and secondary cherts across Italy (Apulia, Basilicata, Sicily), Croatia, and Switzerland, belonging to formations from the Cretaceous to the Quaternary Period. All the chert samples were described according to the non-destructive multiparametric protocol for chert investigation (NM-PCI), providing a modular dataset of binary, ordinal and continuous variables which integrates petrographycal, micropaleontological, chemical and physical data. Such results were summarized in suitable reports, with also geographic coordinates, geological description and photographic documentation, in a digital database, which will be soon online. Cherts are grouped in 37 suitable boxes, following geographic hierarchical organisation and reporting informative labels. Some representative samples are exposed in the Earth Sciences Museum of the same University. Furthermore, the lithotheque is equipped by a dedicated laboratory which includes optical microscopes, a glossmeter and a spectrophotocolorimeter. The promotion in the last years was guaranteed by dissemination activities for educational and academic communities, including an interactive laboratory of experimental archaeology