484 research outputs found

    Magneto-optical characterization of MnxGe1-x alloys obtained by ion implantation

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    Magneto-optical Kerr effect hysteresis loops at various wavelengths in the visible/near-infrared range have been used to characterize the magnetic properties of alloys obtained by implanting Mn ions at fixed energy in a Ge matrix. The details of the hysteresis loops reveal the presence of multiple magnetic contributions. They may be attributed to the inhomogeneous distribution of the magnetic atoms and, in particular, to the known coexistence of diluted Mn in the Ge matrix and metallic Mn-rich nanoparticles embedded in it [Phys. Rev. B 73, 195207(2006)].Comment: 2 pages, 2 figures. Proceeding of the International Conference on Magnetism. Kyoto, August 20-25 200

    Hydrogen induced optically-active defects in silicon photonic nanocavities

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    This work was supported by Era-NET NanoSci LECSIN project coordinated by F. Priolo, by the Italian Ministry of University and Research, FIRB contract No. RBAP06L4S5 and by the EPSRC UKSp project. Partial financial support by the Norwegian Research Council is also acknowledged.We demonstrate intense room temperature photoluminescence (PL) from optically active hydrogen- related defects incorporated into crystalline silicon. Hydrogen was incorporated into the device layer of a silicon on insulator (SOI) wafer by two methods: hydrogen plasma treatment and ion implantation. The room temperature PL spectra show two broad PL bands centered at 1300 and 1500 nm wavelengths: the first one relates to implanted defects while the other band mainly relates to the plasma treatment. Structural characterization reveals the presence of nanometric platelets and bubbles and we attribute different features of the emission spectrum to the presence of these different kind of defects. The emission is further enhanced by introducing defects into photonic crystal (PhC) nanocavities. Transmission electron microscopy analyses revealed that the isotropicity of plasma treatment causes the formation of a higher defects density around the whole cavity compared to the ion implantation technique, while ion implantation creates a lower density of defects embedded in the Si layer, resulting in a higher PL enhancement. These results further increase the understanding of the nature of optically active hydrogen defects and their relation with the observed photoluminescence, which will ultimately lead to the development of intense and tunable crystalline silicon light sources at room temperature.Publisher PDFPeer reviewe

    Fatty acid metabolism in lambs fed citrus pulp

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    Prevalence of Blood Types and Alloantibodies of the AB Blood Group System in Non-Pedigree Cats from Northern (Lombardy) and Southern (Sicily) Italy

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    The aims of this study were to determine the prevalence of A, B and AB blood types and alloantibodies in non-pedigree cats from two regions, one in Northern and one in Southern Italy (Lombardy and Sicily, respectively). A total of 448 samples (52.0% from Northern and 48.0% from Southern Italy) were blood typed. The prevalence of A, B and AB blood types in northern and southern cats were 91.0%, 5.2%, 3.8%, and 77.2%, 12.1% and 10.7%, respectively. The prevalence of type-A blood in southern cats was significantly lower (p = 0.0001) than in northern cats, while type-B and AB blood were significantly higher (p = 0.0085 and p = 0.0051, respectively) in Southern compared to Northern Italian cats. Alloantibodies against type-A blood were found in 94.1% of type-B cats, 11.2% of type-A cats had alloantibodies against type-B blood, while no type-AB cats had alloantibodies with no significant difference between the two Italian populations. Type-AB prevalence in non-pedigree cats in Southern Italy was the highest reported in Europe. Italian type-A cats had the lowest worldwide prevalence of alloantibodies against type-B blood. These results highlight the usefulness of regional studies to report different prevalences in feline blood types and reinforce the importance of blood typing cats before transfusions and mating

    Lamb meat colour stability as affected by dietary tannins

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    Twenty-one male Comisana lambs were divided into three groups at 45 days of age and were individually penned for 60 days. Seven lambs were fed a concentrate-based diet (C), seven lambs received the same concentrate with the addiction of tannins from quebracho (Schinopsis lorentzii; T), whereas the remaining animals were fed exclusively fresh vetch (Vicia sativa; H). Colour descriptors (a*, b* and H*) and metmyoglobin (MMb) percentages were measured on minced semimembranosus muscle over 14 days of refrigerated storage in a high oxygen atmosphere. Regardless of dietary treatment, meat redness decreased, while yellowness and hue angle increased (P < 0.001) over storage duration. However, higher a* values, lower b* values and lower H* values were observed in meat from both H- and T-fed animals as compared to meat from C-fed lambs (P = 0.012; P = 0.02; P = 0.003, respectively). Metmyoglobin formation increased over time (P < 0.001), but H diet resulted in lower metmyoglobin percentages than C diet (P = 0.007). We conclude that the inclusion of tannins into the concentrate improved meat colour stability compared to a tannin-free concentrate. Moreover, the protective effect of tannins against meat discolouration was comparable to that obtained by feeding lambs fresh herbage

    Effect of different dietary tannin extracts on lamb growth performances and meat oxidative stability: comparison between mimosa, chestnut and tara.

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    Little information is available on the effects of different sources of tannins on ruminant product quality. Nowadays several tannin-rich extracts, produced from different plants, are available and contain tannins belonging to different chemical groups, but most of these have not been used so far as feed supplements. The present study aimed at comparing the effects of feeding three tannin extracts (one containing condensed tannins and two containing hydrolysable tannins) to lambs on growth performances and meat oxidative stability. Comisana male lambs were divided into four groups (n=9 each) and were fed for 75 days: a concentrate-based diet (CON), or CON supplemented with 4% tannin extracts from either mimosa (MI; Acacia mearnsii, De Wild; condensed tannins), chestnut (CH; Castanea sativa, Mill; hydrolysable ellagitannins) or tara (TA; Cesalpinia spinosa, (Molina) Kuntze; hydrolysable gallotannins). Only CH reduced growth rate, final weight, carcass weight and feed intake (P0.05). The TA diet increased (P<0.001) the concentration of γ-tocopherol in muscle and tended to increase that of α-tocopherol (P=0.058). Oxidative stability of raw and cooked meat, or of meat homogenates incubated with pro-oxidants, was not affected by the extracts. These results, compared with those reported in the literature, highlight that some effects of tannins cannot be easily generalized, but may strictly depend on their specific characteristics and on conditions inherent to the basal diet and the metabolic status of the animals

    Dog erythrocyte antigens (DEA) 1, 4, 7 and suspected naturally occurring anti-DEA 7 antibodies in italian corso dogs

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    We sought to determine the prevalence of dog erythrocyte antigen (DEA) 1, 4 and 7 and naturally occurring anti-DEA7 antibodies in Italian Corso dogs. In addition, we correlated DEAs with different epidemiologic variables, compared the prevalence of DEAs against other canine populations and assessed the risk of sensitisation and transfusion reactions (TRs) following unmatched transfusion. Blood samples from 100 Corso dogs were evaluated for DEA 1, 4, 7 and naturally occurring anti-DEA 7 antibodies. Seventy-one percent of samples were DEA 1-negative, 100% tested DEA 4-positive, and 95% tested DEA 7-negative. Suspected anti-DEA7 antibodies were found in 32% dogs. The DEA 1 and 7-negative phenotypes were significantly more common than in most canine populations. When a previously tested Italian canine population was considered as blood donors for Corso dogs, the risk of DEA 1 sensitisation using DEA 1 untyped blood was 29%, and of acute haemolytic TRs after a second untyped DEA 1-incompatible transfusion was 8%. The potential for delayed TRs between DEA 7-negative Corso dogs with suspected naturally occurring anti-DEA 7 antibodies receiving untyped DEA 7-positive blood was 11%. Conversely, when Corso dogs were blood donors for the same population, the risk of DEA 1 sensitisation was 17% and the risk of an acute haemolytic TR after a second DEA 1-incompatible blood transfusion was 3%. Corso dogs can be suitable blood donors. Additional studies are needed to clarify whether the high prevalence of naturally occurring anti-DEA 7 antibodies in this breed could increase their risk of delayed TRs when they are blood recipients

    Role of interface region on the optoelectronic properties of silicon nanocrystals embedded in SiO2

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    Light emitting silicon nanocrystals embedded in SiO2 have been investigated by x-ray absorption measurements in total electron and photoluminescence yields, by energy filtered TEM analysis and by ab-initio total energy calculations. Both experimental and theoretical results show that the interface between the silicon nanocrystals and the surrounding SiO2 is not sharp: an intermediate region of amorphous nature and of variable composition links the crystalline Si with the amorphous stoichiometric SiO2. This region plays an active role in the light emission process

    Radiological Features of Male Breast Neoplasms: How to Improve the Management of a Rare Disease

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    The primary aim of our study was to assess the main mammographic and ultrasonographic features of invasive male breast malignancies. The secondary aim was to evaluate whether a specific radiological presentation would be associated with a worse receptor profile. Radiological images (mammography and/or ultrasound) of all patients who underwent surgery for male invasive breast cancer in our institution between 2008 and 2023 were retrospectively analyzed by two breast radiologists in consensus. All significant features of radiological presentation known in the literature were re-evaluated. Fifty-six patients were selected. The mean age at surgery of patients was 69 years (range: 35-81); in 82% of cases (46 patients), the histologic outcome was invasive ductal carcinoma. A total of 28 out of 56 (50%) patients had preoperative mammography; in 9/28 cases (32%), we found a mass with microcalcifications on mammography. The mass presented high density in 25 out of 28 patients (89%); the mass showed irregular margins in 15/28 (54%) cases. A total of 46 out of 56 patients had preoperative ultrasounds. The lesion showed a solid mass in 41/46 (89%) cases. In 5/46 patients (11%), the lesion was a mass with a mixed (partly liquid-partly solid) structure. We did not find any statistically significant correlation between major types of radiological presentation and tumor receptor arrangement. Knowledge of the main radiologic presentation patterns of malignant male breast neoplasm can help better manage this type of disease, which is rare but whose incidence is increasing
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