The iridium double perovskite Sr2YIrO6 revisited: A combined structural and specific heat study

Recently, the iridate double perovskite Sr$_2$YIrO$_6$ has attracted considerable attention due to the report of unexpected magnetism in this Ir$^{5+}$ (5d$^4$) material, in which according to the J$_{eff}$ model, a non-magnetic ground state is expected. However, in recent works on polycrystalline samples of the series Ba$_{2-x}$Sr$_x$YIrO$_6$ no indication of magnetic transitions have been found. We present a structural, magnetic and thermodynamic characterization of Sr$_2$YIrO$_6$ single crystals, with emphasis on the temperature and magnetic field dependence of the specific heat. Here, we demonstrate the clue role of single crystal X-ray diffraction on the structural characterization of the Sr$_2$YIrO$_6$ double perovskite crystals by reporting the detection of a $\sqrt{2}a \times \sqrt{2}a \times 1c$ supercell, where $a$, $b$ and $c$ are the unit cell dimensions of the reported monoclinic subcell. In agreement with the expected non-magnetic ground state of Ir$^{5+}$ (5d$^4$) in Sr$_2$YIrO$_6$, no magnetic transition is observed down to 430~mK. Moreover, our results suggest that the low temperature anomaly observed in the specific heat is not related to the onset of long-range magnetic order. Instead, it is identified as a Schottky anomaly caused by paramagnetic impurities present in the sample, of the order of $n \sim 0.5(2)$ \%. These impurities lead to non-negligible spin correlations, which nonetheless, are not associated with long-range magnetic ordering.Comment: 20 pages, 10 figure

Lupus vulgaris reported in 2 cases

Department of Dermatovenerology, State University of Medicine and Pharmacy "Nicolae Testemitanu", Chișinău, Republic of Moldova, Congresul consacrat aniversării a 75-a de la fondarea Universității de Stat de Medicină și Farmacie „Nicolae Testemițanu” din Republica Moldova, Ziua internațională a științei pentru pace și dezvoltareIntroduction: Cutaneous tuberculosis is a group of polymorphous and varied manifestations of the skin and mucous membranes, produced by infection with some species of Mycobacterium tuberculosis complex. The specific primary lesion is the lupoma, sometimes evolving into mutilating forms. Purpose: Lupus vulgaris particularities reported in two clinical cases. Material and methods: A 68-year-old female, presented for multiple infiltrative, prominent erythematous plaques and placards with various diameter, well contoured by a violaceus halo, with irregular contour on the trunk. A 6-year-old boy presented for brownish-red, soft papules with smooth surface on the face and trunk. The lesions appeared 3 years ago; and 6 months ago after a minor trauma injury, the lesions have spread. Results: Chest X-ray didn’t reveal any abnormalities. During dermascopy the sign of “apple jelly” was found positive. Histopathological exam found caseous necrosis, tuberculoid granulomas composed of epithelioid cells and Langhans giant cells, surrounded by mononuclear and a dense lymphocyte infiltrate localized in the dermis. Mantoux probe was 17 mm in diameter. Clinical examination sustained by the histopathological exam and Mantoux probe inferred the diagnosis of lupus vulgaris (tuberculosis). Conclusions: The particularities of the presented cases with distinct clinical signs, the histopathological presence of granulomatous inflammation with specific cellular appearance, the hyperergic Mantoux test and the lack of characteristic pulmonary changes represent a casuistic interest of lupus vulgaris

First record of Dysmicoccus boninsis Kuwana, 1909 (Hemiptera: Pseudococcidae) on sugarcane in the state of Rio Grande do Sul.

Among the sap-sucking insects that infest sugarcane [Saccharum spp. (Poaceae)] around the world, scale insects (Hemiptera: Coccomorpha) stand out with 103 recorded species. Most of them are frequently regarded as secondary or occasional pests (Garcia Morales et al., 2016). In Brazil, eighteen species of scale insects have already been reported on sugarcane. Of these, Aclerda takahashii (Kuwana, 1932) (Aclerdidae), Margarodes sp., (Margarodidae) and Saccharicoccus sacchari (Cockerell, 1895) (Pseudococcidae) are known to the state of Rio Grande do Sul (Garcia Morales et al., 2016; Borges Filho et al., 2019; Monteiro et al., 2019).First online

A Comprehensive Pediatric Asthma Management Program Reduces Emergency Department Visits and Hospitalizations

We evaluated the impact of a comprehensive pediatric asthma management program (the Children's Asthma Wellness Program, CAWP) on the frequency of emergency department (ED) visits and hospital admissions. The CAWP generally consisted of 4 clinic sessions over a 1-year period, but some patients attended fewer clinic sessions, and some required additional clinic sessions due to incomplete asthma control. Patients were evaluated and treated by pediatric pulmonologists, nurse asthma care coordinator/educator, and social worker. We retrospectively reviewed program results over an 8-year period (2005?2013). We compared ED visits and hospital admissions before and after participation in the CAWP. There were 254 children referred to the CAWP; 172 children were enrolled. Fifty-four children (31%) received >6 sessions due to incomplete asthma control. On average, children requiring additional clinic sessions were older and more likely to be African American, hold Medicaid insurance, and have severe asthma. We obtained a minimum of 1-year preprogram and 1-year postprogram administrative data for 86 children (50%). Using each participating child as his/her own control, we found that taking part in the program decreased the risk of ED visits to 0.26 times the preprogram rate (P?Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140178/1/ped.2015.0561.pd

Strongly correlated superconductor with polytypic 3D Dirac points

Topological superconductors should be able to provide essential ingredients for quantum computing, but are very challenging to realize. Spin-orbit interaction in iron-based superconductors opens the energy gap between the $p$-states of pnictogen and $d$-states of iron very close to the Fermi level, and such $p$-states have been recently experimentally detected. Density functional theory predicts existence of topological surface states within this gap in FeTe$_{1-x}$Se$_x$ making it an attractive candidate material. Here we use synchrotron-based angle-resolved photoemission spectroscopy and band structure calculations to demonstrate that FeTe$_{1-x}$Se$_x$ (x=0.45) is a superconducting 3D Dirac semimetal hosting type-I and type-II Dirac points and that its electronic structure remains topologically trivial. We show that the inverted band gap in FeTe$_{1-x}$Se$_x$ can possibly be realized by further increase of Te content, but strong correlations reduce it to a sub-meV size, making the experimental detection of this gap and corresponding topological surface states very challenging, not to mention exact matching with the Fermi level. On the other hand, the $p-d$ and $d-d$ interactions are responsible for the formation of extremely flat band at the Fermi level pointing to its intimate relation with the mechanism of high-T$_c$ superconductivity in IBS.Comment: 10 pages, 5 figures, 28 reference