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1.
Phys Rev Lett ; 124(17): 171801, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32412290

RESUMEN

A ferromagnetic axion haloscope searches for dark matter in the form of axions by exploiting their interaction with electronic spins. It is composed of an axion-to-electromagnetic field transducer coupled to a sensitive rf detector. The former is a photon-magnon hybrid system, and the latter is based on a quantum-limited Josephson parametric amplifier. The hybrid system consists of ten 2.1 mm diameter yttrium iron garnet spheres coupled to a single microwave cavity mode by means of a static magnetic field. Our setup is the most sensitive rf spin magnetometer ever realized. The minimum detectable field is 5.5×10^{-19} T with 9 h integration time, corresponding to a limit on the axion-electron coupling constant g_{aee}≤1.7×10^{-11} at 95% C.L. The scientific run of our haloscope resulted in the best limit on dark matter axions to electron coupling constant in a frequency span of about 120 MHz, corresponding to the axion-mass range 42.4-43.1 µeV. This is also the first apparatus to perform a wide axion-mass scanning by only changing the static magnetic field.

2.
Rev Sci Instrum ; 91(9): 094701, 2020 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33003802

RESUMEN

Searches for dark matter axions involve the use of microwave resonant cavities operating in a strong magnetic field. Detector sensitivity is directly related to the cavity quality factor, which is limited, until recently, to the use of non-superconducting metals by the presence of the external magnetic field. In this paper, we present a cavity of novel design whose quality factor is not affected by a magnetic field. It is based on a photonic structure by the use of sapphire rods. The quality factor at cryogenic temperature is in excess of 5 × 105 for a selected mode.

3.
Poult Sci ; 85(4): 787-93, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16615364

RESUMEN

The color of food, especially meat and meat products, is a parameter that strongly influences consumer choice. In Italy, repeated cases of darkening in deboned thigh meat of male turkeys packaged in modified atmosphere (MAP; 80% 02, 20% CO2) have been reported. The pH, lipid oxidation (TBARS), heme proteins, and iron content were investigated in MAP samples of turkey males, females, and in oxygen-permeable film-packaged males. Furthermore, the absorbance spectrum (400 to 700 nm) of the meat extracts was analyzed to better delineate the evolution and characteristics of the darkening process. Results showed that darkening occurred only in males with higher content of total iron, independently of the content of heme proteins, which differs only between males and females. Furthermore, pH was higher in muscles taken as controls, with respect to muscles involved in the darkening, as well as in females. Finally, TBARS values were found to be higher in darkened regions than in not darkened ones, as well as in MAP samples with respect to oxygen-permeable film-packaged samples. These findings suggest that darkening occurrence might depend on kind of muscle, sex, and individual characteristics of the animals raised under the same breeding conditions.


Asunto(s)
Atmósfera/química , Color , Embalaje de Alimentos/métodos , Carne/análisis , Pavos , Animales , Femenino , Hemoproteínas/análisis , Concentración de Iones de Hidrógeno , Hierro/análisis , Italia , Peroxidación de Lípido , Masculino , Caracteres Sexuales
7.
Res Vet Sci ; 87(1): 29-35, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19062055

RESUMEN

A study was performed to delineate bST and IGF-1 variation, over a whole lactation, in cows treated with a nowadays widely commercialised but little studied sustained release formulation of recombinant bST. Total bST levels were found to be exceptionally high in the first days after administration, but decreased rapidly in the second week after injection. The increase in the IGF-1 serum concentration was significant for almost the entire biweekly cycle. Based on this study, the peaks of ST (often above 100 ng/ml) are considered particularly unlikely to be found in non-treated bovines, even under pathological conditions, especially when detected in a number of animals within a herd. Notwithstanding the great heterogeneity of results on this topic, these data suggest that tests against fraud involving the use of rbST in dairy products may be regarded as a feasible possibility.


Asunto(s)
Bovinos/sangre , Bovinos/metabolismo , Hormona del Crecimiento/sangre , Hormona del Crecimiento/farmacología , Factor I del Crecimiento Similar a la Insulina/metabolismo , Proteínas Recombinantes/farmacología , Animales , Preparaciones de Acción Retardada , Femenino , Hormona del Crecimiento/administración & dosificación , Lactancia/fisiología
8.
Acta Neurol Scand ; 80(4): 282-6, 1989 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2683557

RESUMEN

Nimodipine (BAY e 9736), a new dihydropyridine derivative, has been shown to reduce neurological deficits and mortality induced by acute cerebral ischemia in experimental studies. We investigated the effects of this calcium antagonist in patients with acute ischemic stroke through a randomized, double-blind, parallel-designed trial in which nimodipine was compared with placebo. Forty-one of 54 screened cases were found to fulfil the inclusion criteria (sudden occurrence of a focal neurological deficit secondary to an acute ischemic event in the carotid area diagnosed after a complete neurological work-up) and entered the study. Nineteen of them were treated with nimodipine (40 mg t.i.d. administered for 28 days) and the remaining 22 with placebo, given in identical tablets. In all patients the treatment started within 12 h after the onset of the symptoms. Course and intensity of the neurological deficit were evaluated by the Mathew Scale (slightly modified). Forty patients concluded the trial. Nimodipine was withdrawn in one case following the occurrence of a skin rash whose causative relation with the test drug could not be clarified. Altogether, however, nimodipine was well tolerated and no severe cardiovascular adverse reactions were observed. In terms of efficacy, the scores obtained by the Mathew Scale showed a higher rate of improvement on nimodipine than on placebo, thus indicating that patients receiving the latter drug did not fare as well as those receiving the test medication. Our data suggest that nimodipine may be beneficial in the treatment of acute stroke.


Asunto(s)
Isquemia Encefálica/tratamiento farmacológico , Nimodipina/administración & dosificación , Enfermedad Aguda , Administración Oral , Anciano , Presión Sanguínea , Método Doble Ciego , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Persona de Mediana Edad , Nimodipina/uso terapéutico , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto
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