1,209 research outputs found

    Neutron electric dipole moment from gauge/string duality

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    We compute the electric dipole moment of nucleons in the large NcN_c QCD model by Witten, Sakai and Sugimoto with Nf=2N_f=2 degenerate massive flavors. Baryons in the model are instantonic solitons of an effective five-dimensional action describing the whole tower of mesonic fields. We find that the dipole electromagnetic form factor of the nucleons, induced by a finite topological θ\theta angle, exhibits complete vector meson dominance. We are able to evaluate the contribution of each vector meson to the final result - a small number of modes are relevant to obtain an accurate estimate. Extrapolating the model parameters to real QCD data, the neutron electric dipole moment is evaluated to be dn=1.8⋅10−16 θ  e⋅cmd_n = 1.8 \cdot 10^{-16}\, \theta\;e\cdot \mathrm{cm}. The electric dipole moment of the proton is exactly the opposite.Comment: Latex, 4 pages; v2: minor corrections, few comments adde

    Quality of reporting on the vegetative state in Italian newspapers. The case of Eluana Englaro.

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    Background: Media coverage of the vegetative state (VS) includes refutations of the VS diagnosis and describes behaviors inconsistent with VS. We used a quality score to assess the reporting in articles describing the medical characteristics of VS in Italian newspapers. Methodology/Principal Findings: Our search covered a 7-month period from July 1, 2008, to February 28, 2009, using the online searchable databases of four major Italian newspapers: Corriere della Sera, La Repubblica, La Stampa, and Avvenire. Medical reporting was judged as complete if three core VS characteristics were described: patient unawareness of self and the environment, preserved wakefulness (eyes open), and spontaneous respiration (artificial ventilator not needed). We retrieved 2,099 articles, and 967 were dedicated to VS. Of these, 853 (88.2%) were non-medical and mainly focused on describing the political, legal, and ethical aspects of VS. Of the 114 (11.8%) medical articles, 53 (5.5%) discussed other medical problems such as death by dehydration, artificial nutrition, neuroimaging, brain death, or uterine hemorrhage, and 61 (6.3%) described VS. Of these 61, only 18 (1.9%) reported all three CORE characteristics and were judged complete. We found no differences among the four investigated newspapers (Fisher’s exact = 0.798), and incomplete articles were equally distributed between journalistic pieces and expert opinions (x2 = 1.8854, P = 0.170). Incorrect descriptions of VS were significantly more common among incomplete articles (13 of 43 vs. 1 of 18; Fisher’s exact P = 0.047). Conclusions/Significance: Core VS characteristics are rarely reported in Italian newspaper articles, which can alter adequate comprehension of new developments and (mis)inform political, legal, and ethical decisions

    Liquid Argon Time Projection Chambers for Dark Matter and Neutrino Experiments

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    This thesis illustrates the contribution of the author to experiments using liquid argon Time Projection Chambers (LAr TPCs), a technology already widely used, that is becoming the dominating detection technique in dark matter (DM) and neutrino searches

    Deep inside of gastric signet-ring cell carcinoma

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    The histology of signet-ring cell carcinoma (SRC) of the stomach has been revisited with the support of current immunohistochemical techniques in order to explain particular features of this tumor; its great capacity of local diffusion and lymph node metastasis, also through a neo-lymphoangiogenesis. An observational retrospective study on 50 cases of SRC in stage II and III has been performed with the addition of histochemical (Alcian Blue, DDD-Fast Blue B, Mercury Orange) and immunohistochemical (cytocheratin, CD3, CD4, CD8, CD10, CD56, CD68, perforin, granzyme B, podoplanin, collagen type IV) investigations for each case. The signet ring cells, typical for this tumor, show abundant content of electro-negative sialomucins and demonstrate a great capacity of diffusion through the gastric wall. They evoke production and deposition of collagen type IV in the sub-mucosa layer through the local action of fibroblasts. The immunological response to this tumor in the gastric wall and in the metastatic lymph nodes is represented by an increase of B and T-helper lymphocytes, but not of T-killers or natural killers. The neoplastic cells are curiously able to avoid these newly formed ‘lymph nodules’. An extended neo-lymphangiogenesis has been observed around the primary tumor and in metastatic lymph nodes. A careful immunohistochemical characterization has allowed a better knowledge of SRC, regarding especially the peculiar behavior of local diffusion of its cells, the associated neo-lymph angiogenesis, and poor immunological reaction

    Liver injury by experimental portal bacteremia: histogenetic recovery study in the rat

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    Abstract - To study the histogenetic recovery of hepatic lesions due to portal bacteremia, a complication of some clinical conditions, an experimental animal model had developed. Portal bacteremia was performed in 8-week rats and the morphological recovery of liver was histologically checked 1 to 6 days after bacteria inoculation. The major injuries, such as acute inflammatory exudate of the portobiliary spaces, piecemeal necrosis of muralium, micro-abscesses and areas of hepatocyte necrosis of the liver parenchyma, and thrombosis in the centrolobular vein were recorded 1 day after inoculation. Minimal signs of vacuolar degeneration, steatosis, necrosis areas, vessel congestion and focal hemosiderosis together with a small hepatocyte proliferative activity was instead appreciable with longer time. The results seem to suggest a role of vascular structures and Kupffer cells in the morphological repair. This experimental model could serve to understand better similar clinical hepatology conditions, such as portal bacteremia.Informazioni util
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