116 research outputs found

    Magnetically induced metal-insulator transition in Pb2CaOsO6

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    We report on the structural, magnetic, and electronic properties of two new double-perovskites synthesized under high pressure, Pb2CaOsO6 and Pb2ZnOsO6. Upon cooling below 80 K, Pb2CaOsO6 simultaneously undergoes a metal-to-insulator transition and develops antiferromagnetic order. Pb2ZnOsO6, on the other hand, remains a paramagnetic metal down to 2 K. The key difference between the two compounds lies in their crystal structures. The Os atoms in Pb2ZnOsO6 are arranged on an approximately face-centered cubic lattice with strong antiferromagnetic nearest-neighbor exchange couplings. The geometrical frustration inherent to this lattice prevents magnetic order from forming down to the lowest temperatures. In contrast, the unit cell of Pb2CaOsO6 is heavily distorted up to at least 500 K including antiferroelectriclike displacements of the Pb and O atoms despite metallic conductivity above 80 K. This distortion relieves the magnetic frustration, facilitating magnetic order which, in turn, drives the metal-insulator transition. Our results suggest that the phase transition in Pb2CaOsO6 is spin driven and could be a rare example of a Slater transition

    Acinic Cell Carcinoma with Extensive Neuroendocrine Differentiation: A Diagnostic Challenge

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    Primary salivary gland carcinoma with neuroendocrine differentiation is of rare occurrence, especially so in the parotid gland. Amongst the various reported primary tumors with neuroendocrine differentiation, acinic cell carcinoma (ACC) one such tumor. A 48 year old lady presented with a gradually increasing right infra-auricular swelling for a period of 1 year which enlarged suddenly in a short period. Contrast Enhanced Computed Tomography (CECT) suggested diagnosis of Pleomorphic Adenoma. Fine Needle Aspiration Cytology (FANC) yielded a cystic fluid suggesting a possibility of Warthin’s tumor or Oncocytic lesion. Intraoperative findings were suggestive of a Warthin’s tumor. Initial histopathological examination of the tumor was suggestive of neuroendocrine carcinoma. However, extensive sectioning revealed peripheral islands of ACC. Immunoexpression of S-100, Neuron specific Enolase (NSE), Chromogranin A and Synaptophysin confirmed the diagnosis. The possibility of neuroendocrine differentiation in a primary salivary gland tumor should be kept in mind whenever a salivary gland tumor shows only neuroendocrine histology

    Soft tissue mixed tumor of the hand

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    Mixed tumors are relatively common in the skin and salivary glands, but extremely rare in soft tissues, often resulting in diagnostic problems. The occurrence of these tumors in the hand is especially limited. In this article we report the clinical, radiological, and histological features of a mixed tumor of the hypothenar region of the right hand

    Reproductive performance in sows in relation to Japanese Encephalitis Virus seropositivity in an endemic area

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    Japanese Encephalitis Virus (JEV) is considered an important reproductive pathogen in pigs. Most studies of the reproductive impact of JEV have been conducted in areas where the disease occurs in seasonal epidemics. In this study, the associations between seropositivity for JEV, measured with an IgG ELISA, and the number of piglets born alive and stillborn were investigated in a tropical area endemic for JEV in Vietnam. Sixty percent of sows from four farms in the Mekong delta of Vietnam were seropositive to JEV and the Odds Ratio for a sow being infected was highest (6.4) in sows above 3.5 years (95% confidence interval 2.2–18.3). There was an association between increasing Optical Density (OD) values from the ELISA and the number of stillborn piglets in sows less than 1.5 years, but no effect of seropositivity could be shown when all sows were studied. OD values had an effect (p = 0.04) on the number of piglets born alive in the statistical analysis only when interacting with the effect of the breeds. An increase in mean OD value of the herd was correlated (p < 0.0001) with an increase in the number of piglets born alive. In this study, there was evidence of a negative association between seropositivity for JEV and the reproductive performance only in sows less than 1.5 years in endemic areas. This could be explained by a year-round infection with the virus, which would lead to immunity in many gilts before their first pregnancy. This, in turn, may imply that JEV infection in pigs is of minor importance for the reproductive performance in endemic areas

    A patient with hypereosinophilic syndrome that manifested with acquired hemophilia and elevated IgG4: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Hypereosinophilic syndrome is defined as a prolonged state (more than six months) of eosinophilia (greater than 1500 cells/μL), without an apparent etiology and with end-organ damage. Hypereosinophilic syndrome can cause coagulation abnormalities. Among hypereosinophilic syndrome types, the lymphocytic variant (lymphocytic hypereosinophilic syndrome) is derived from a monoclonal proliferation of T lymphocytes. Here, we describe the case of a patient with lymphocytic hypereosinophilic syndrome who presented with a coagulation abnormality. To the best of our knowledge, this is the first such report including a detailed clinical picture and temporal cytokine profile.</p> <p>Case presentation</p> <p>A 77-year-old Japanese man presented to our facility with massive hematuria and hypereosinophilia (greater than 2600 cells/μl). His eosinophilia first appeared five years earlier when he developed femoral artery occlusion. He manifested with multiple hematomas and prolonged activated partial thromboplastin time. His IgG4 level was remarkably elevated (greater than 2000 mg/dL). Polymerase chain reaction tests of peripheral blood and bone marrow identified lymphocytic hypereosinophilic syndrome. His prolonged activated partial thromboplastin time was found to be due to acquired hemophilia. Glucocorticoids suppressed both the hypereosinophilia and coagulation abnormality. However, tapering of glucocorticoids led to a relapse of the coagulation abnormality alone, without eosinophilia. Tumor necrosis factor α, interleukin-5, and/or eotaxin-3 may have caused the hypereosinophilia, and interleukin-10 was correlated with the coagulation abnormality.</p> <p>Conclusions</p> <p>To the best of our knowledge, this is the first case in which lymphocytic hypereosinophilic syndrome and IgG4-related disease have overlapped. In addition, our patient is only the second case of hypereosinophilic disease that manifested with acquired hemophilia. Our patient relapsed with the coagulation abnormality alone, without eosinophilia. This report shows that the link between eosinophilia, IgG4, and clinical manifestations is not simple and provides useful insight into the immunopathology of hypereosinophilic syndrome and IgG4-related disease.</p

    Increasing vegetable intakes: rationale and systematic review of published interventions

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    Purpose While the health benefits of a high fruit and vegetable consumption are well known and considerable work has attempted to improve intakes, increasing evidence also recognises a distinction between fruit and vegetables, both in their impacts on health and in consumption patterns. Increasing work suggests health benefits from a high consumption specifically of vegetables, yet intakes remain low, and barriers to increasing intakes are prevalent making intervention difficult. A systematic review was undertaken to identify from the published literature all studies reporting an intervention to increase intakes of vegetables as a distinct food group. Methods Databases—PubMed, PsychInfo and Medline—were searched over all years of records until April 2015 using pre-specified terms. Results Our searches identified 77 studies, detailing 140 interventions, of which 133 (81 %) interventions were conducted in children. Interventions aimed to use or change hedonic factors, such as taste, liking and familiarity (n = 72), use or change environmental factors (n = 39), use or change cognitive factors (n = 19), or a combination of strategies (n = 10). Increased vegetable acceptance, selection and/or consumption were reported to some degree in 116 (83 %) interventions, but the majority of effects seem small and inconsistent. Conclusions Greater percent success is currently found from environmental, educational and multi-component interventions, but publication bias is likely, and long-term effects and cost-effectiveness are rarely considered. A focus on long-term benefits and sustained behaviour change is required. Certain population groups are also noticeably absent from the current list of tried interventions

    Observations of Lyα\alpha Emitters at High Redshift

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    In this series of lectures, I review our observational understanding of high-zz Lyα\alpha emitters (LAEs) and relevant scientific topics. Since the discovery of LAEs in the late 1990s, more than ten (one) thousand(s) of LAEs have been identified photometrically (spectroscopically) at z0z\sim 0 to z10z\sim 10. These large samples of LAEs are useful to address two major astrophysical issues, galaxy formation and cosmic reionization. Statistical studies have revealed the general picture of LAEs' physical properties: young stellar populations, remarkable luminosity function evolutions, compact morphologies, highly ionized inter-stellar media (ISM) with low metal/dust contents, low masses of dark-matter halos. Typical LAEs represent low-mass high-zz galaxies, high-zz analogs of dwarf galaxies, some of which are thought to be candidates of population III galaxies. These observational studies have also pinpointed rare bright Lyα\alpha sources extended over 10100\sim 10-100 kpc, dubbed Lyα\alpha blobs, whose physical origins are under debate. LAEs are used as probes of cosmic reionization history through the Lyα\alpha damping wing absorption given by the neutral hydrogen of the inter-galactic medium (IGM), which complement the cosmic microwave background radiation and 21cm observations. The low-mass and highly-ionized population of LAEs can be major sources of cosmic reionization. The budget of ionizing photons for cosmic reionization has been constrained, although there remain large observational uncertainties in the parameters. Beyond galaxy formation and cosmic reionization, several new usages of LAEs for science frontiers have been suggested such as the distribution of {\sc Hi} gas in the circum-galactic medium and filaments of large-scale structures. On-going programs and future telescope projects, such as JWST, ELTs, and SKA, will push the horizons of the science frontiers.Comment: Lecture notes for `Lyman-alpha as an Astrophysical and Cosmological Tool', Saas-Fee Advanced Course 46. Verhamme, A., North, P., Cantalupo, S., & Atek, H. (eds.) --- 147 pages, 103 figures. Abstract abridged. Link to the lecture program including the video recording and ppt files : https://obswww.unige.ch/Courses/saas-fee-2016/program.cg

    The disruption of proteostasis in neurodegenerative diseases

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    Cells count on surveillance systems to monitor and protect the cellular proteome which, besides being highly heterogeneous, is constantly being challenged by intrinsic and environmental factors. In this context, the proteostasis network (PN) is essential to achieve a stable and functional proteome. Disruption of the PN is associated with aging and can lead to and/or potentiate the occurrence of many neurodegenerative diseases (ND). This not only emphasizes the importance of the PN in health span and aging but also how its modulation can be a potential target for intervention and treatment of human diseases.info:eu-repo/semantics/publishedVersio
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