110 research outputs found

    Electrical Transport Properties Of Iodine Oxide Phosphate Glasses Issued From The NaI-Li2O-WO3-P2O5 System

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    This work concerns the investigation of ion transport behaviour of NaI containing lithium tungsten phosphate glasses in order to understand better the role of NaI in the ionic cation transport. Glasses obtained in the system 0.5[x(2NaI)-(1-x)Li2O]-0.5[0.25(WO3)2-0.75P2O5] were investigated. The glass samples have been characterised using powder X-ray diffraction (XRD), thermal analysis, density and impedance spectroscopy. X-ray diffraction and thermal studies have confirmed that these glasses can be formed in the range x = 0 to 1. The mixed alkali glasses have shown higher activation energies and lower conductivities compared to single alkali doped glasses and this has been attributed to a mixed alkali effect.This work concerns the investigation of ion transport behaviour of NaI containing lithium tungsten phosphate glasses in order to understand better the role of NaI in the ionic cation transport. Glasses obtained in the system 0.5[x(2NaI)-(1-x)Li2O]-0.5[0.25(WO3)2-0.75P2O5] were investigated. The glass samples have been characterised using powder X-ray diffraction (XRD), thermal analysis, density and impedance spectroscopy. X-ray diffraction and thermal studies have confirmed that these glasses can be formed in the range x = 0 to 1. The mixed alkali glasses have shown higher activation energies and lower conductivities compared to single alkali doped glasses and this has been attributed to a mixed alkali effect

    Investigation of the magnetic phase transition and magnetocaloric properties of the Mn2_2FeSbO6_6 ilmenite

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    The magnetic phase transition and magnetocaloric properties of mineral and synthetic melanostibite Mn2_2FeSbO6_6 with ilmenite-type structure have been studied. Mn2_2FeSbO6_6 orders ferrimagnetically below 270 K and is found to undergo a second-order magnetic phase transition. The associated magnetic entropy change amounts to 1.7 J/kgK for the mineral and 1.8 J/kgK synthetic melanostibite for 5 T field change. For the synthetic Mn2_2FeSbO6_6 the adiabatic temperature change was estimated from magnetic- and specific heat measurements and amounts to 0.2 K in 1 T field change. Perspectives of the promising functional properties of Mn2_2FeSbO6_6-based materials are discussed.Comment: 6 pages, 7 figure

    Contact tracing investigation after professional exposure to tuberculosis in a Swiss hospital using both tuberculin skin test and IGRA.

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    SETTING: A 950 bed teaching hospital in Switzerland. AIM: To describe the result of a contact investigation among health care workers (HCW) and patients after exposure to a physician with smear-positive pulmonary tuberculosis in a hospital setting using standard tuberculin skin tests (TST) and Interferon-gamma release assay (IGRA). METHOD: HCW with a negative or unknown TST at hiring had a TST two weeks after the last contact with the index case (T0), repeated six weeks later if negative (T6). All exposed HCW had a T-SPOT.TB at T0 and T6. Exposed patients had a TST six weeks after the last contact, and a T-SPOT.TB if the TST was positive. RESULTS: Among 101 HCW, 17/73 (22%) had a positive TST at T0. TST was repeated in 50 at T6 and converted from negative to positive in eight (16%). Twelve HCW had a positive T-SPOT.TB at T0 and ten converted from negative to positive at T6. Seven HCW with a positive T-SPOT.TB reverted to negative at T6 or at later controls, most of them with test values close to the cut-off. Among 27 exposed patients tested at six weeks, ten had a positive TST, five of them confirmed by a positive T-SPOT.TB. CONCLUSIONS: HCW tested twice after exposure to a case of smear-positive pulmonary TB demonstrated a possible conversion in 10% with T-SPOT and 16% with TST. Some T-SPOT.TB reverted from positive to negative during the follow-up, mostly tests with a value close to the cut-off. Due to the variability of the test results, it seems advisable to repeat the test with values close to the cut-off before diagnosing the presence of a tuberculous infection

    Effect of Nickel Administration in vivo on the Testicular Structure in Male Mice

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    The aim of this study was to describe the effects of nickel (NiCl2) on murine testicular structure. Experimental animals were injected intraperitoneally with a single dose of 20 mg NiCl2 per kg of body mass (group A, n = 5) and 40 mg NiCl2 per kg b. m. (group B, n = 5). The group without injection (n = 5) was the control (C). Animals were killed 48 hours after administration of nickel. The body mass of animals, the mass of testes and the testes : body mass ratio were not significantly affected. In both experimental groups a significant (p p p < 0.05 - 0.001) after nickel administration. Evaluation of the lumen diameter in the seminiferous tubule showed a significant increase in both experimental groups. The data of the perimeter of seminiferous tubules corresponded with those of the seminiferous tubule diameter. TUNEL assay detected a higher frequency of localized apoptosis in the interstitium of nickel-administered animals compared to control group. Our findings clearly suggest a negative effect of nickel on the structure as well as on the function of the seminferous epithelium at the site of spermatozoa production

    Human Bronchial Epithelial Cells Induce CD141/CD123/DC-SIGN/FLT3 Monocytes That Promote Allogeneic Th17 Differentiation.

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    Little is known about monocyte differentiation in the lung mucosal environment and about how the epithelium shapes monocyte function. We studied the role of the soluble component of bronchial epithelial cells (BECs) obtained under basal culture conditions in innate and adaptive monocyte responses. Monocytes cultured in bronchial epithelial cell-conditioned media (BEC-CM) specifically upregulate CD141, CD123, and DC-SIGN surface levels and FLT3 expression, as well as the release of IL-1β, IL-6, and IL-10. BEC-conditioned monocytes stimulate naive T cells to produce IL-17 through IL-1β mechanism and also trigger IL-10 production by memory T cells. Furthermore, monocytes cultured in an inflammatory environment induced by the cytokines IL-6, IL-8, IL-1β, IL-15, TNF-α, and GM-CSF also upregulate CD123 and DC-SIGN expression. However, only inflammatory cytokines in the epithelial environment boost the expression of CD141. Interestingly, we identified a CD141/CD123/DC-SIGN triple positive population in the bronchoalveolar lavage fluid (BALF) from patients with different inflammatory conditions, demonstrating that this monocyte population exists in vivo. The frequency of this monocyte population was significantly increased in patients with sarcoidosis, suggesting a role in inflammatory mechanisms. Overall, these data highlight the specific role that the epithelium plays in shaping monocyte responses. Therefore, the unraveling of these mechanisms contributes to the understanding of the function that the epithelium may play in vivo

    Tuning of dielectric properties and magnetism of SrTiO3 by site-specific doping of Mn

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    Combining experiments with first principles calculations, we show that site-specific doping of Mn into SrTiO3 has a decisive influence on the dielectric properties of these doped systems. We find that phonon contributions to the dielectric constant invariably decrease sharply on doping at any site. However, a sizable, random dipolar contribution only for Mn at the Sr site arises from a strong off-centric displacement of Mn in spite of Mn being in a non-d0 state; this leads to a large dielectric constant at higher temperatures and gives rise to a relaxor ferroelectric behavior at lower temperatures. We also investigate magnetic properties in detail and critically reevaluate the possibility of a true multi-glass state in such systems.Comment: 24 Pages, 2 Tables, 9 Figure

    The influence of obtaining and heat treatment conditions on the structure of As₂S₃-SbSI system

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    (As₂S₃)₁₀₀₋x(SbSI)x (x = 80 and 90) glasses were prepared by cooling homogenized melts from 720…750 K in cold water. Their structure and structural changes under heat treatment of glasses are confirmed by studies of micro-Raman scattering and X-ray diffraction. In the matrix of these glasses, we observed SbSI nanocrystalline inclusions. It has been shown that the sizes of crystalline inclusions are dependent on the heat treatment regimes

    Seventh BHD international symposium: recent scientific and clinical advancement.

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    The 7th Birt-Hogg-Dubé (BHD) International Symposium convened virtually in October 2021. The meeting attracted more than 200 participants internationally and highlighted recent findings in a variety of areas, including genetic insight and molecular understanding of BHD syndrome, structure and function of the tumor suppressor Folliculin (FLCN), therapeutic and clinical advances as well as patients' experiences living with this malady
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