Electronic structure and magnetic properties of the spin-1/2 Heisenberg system CuSe2O5

A microscopic magnetic model for the spin-1/2 Heisenberg chain compound CuSe2O5 is developed based on the results of a joint experimental and theoretical study. Magnetic susceptibility and specific heat data give evidence for quasi-1D magnetism with leading antiferromagnetic (AFM) couplings and an AFM ordering temperature of 17 K. For microscopic insight, full-potential DFT calculations within the local density approximation (LDA) were performed. Using the resulting band structure, a consistent set of transfer integrals for an effective one-band tight-binding model was obtained. Electronic correlations were treated on a mean-field level starting from LDA (LSDA+U method) and on a model level (Hubbard model). In excellent agreement of experiment and theory, we find that only two couplings in CuSe2O5 are relevant: the nearest-neighbour intra-chain interaction of 165 K and a non-frustrated inter-chain coupling of 20 K. From a comparison with structurally related systems (Sr2Cu(PO4)2, Bi2CuO4), general implications for a magnetic ordering in presence of inter-chain frustration are made.Comment: 20 pages, 8 figures, 3 table

Tangled banks: A landscape genomic evaluation of Wallace's Riverine barrier hypothesis for three Amazon plant species

Wallace's Riverine Barrier hypothesis is one of the earliest biogeographic explanations for Amazon speciation, but it has rarely been tested in plants. In this study, we used three woody Amazonian plant species to evaluate Wallace's Hypothesis using tools of landscape genomics. We generated unlinked single‐nucleotide polymorphism (SNP) data from the nuclear genomes of 234 individuals (78 for each plant species) across 13 sampling sites along the Rio Branco, Brazil, for Amphirrhox longifolia (8,075 SNPs), Psychotria lupulina (9,501 SNPs) and Passiflora spinosa (14,536 SNPs). Although significantly different migration rates were estimated between species, the population structure data do not support the hypothesis that the Rio Branco—an allopatric barrier for primates and birds—is a significant genetic barrier for Amphirrhox longifolia, Passiflora spinosa or Psychotria lupulina. Overall, we demonstrated that medium‐ sized rivers in the Amazon Basin, such as the Rio Branco, are permeable barriers to gene flow for animal‐dispersed and animal‐pollinated plant species.National Science Foundation, NASAFundação de Amparo à Pesquisa do Estado de São Paulo, Grant/Award Number: 2013/12633‐8, 2015/07141‐4, 2017/02302‐5 and 2012/50260‐6; Conselho Nacional de Desenvolvimento Científico e Tecnológico, Grant/Award Number: 310871/2017‐4; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Grant/Award Number: 88881.064974/2014‐01; National Science Foundation, Grant/Award Number: FESD 1338694 and DEB 1240869; Universidade de São PauloPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148338/1/Nazareno2019.pdf85Description of Nazareno2019.pdf : Main articl

Features of compensatory angiogenesis of periodontal tissues in eldery patients with generalised periodontitis influenced tunnel revaskularization and quercetin

This article submissions examination and treatment of 30 persons aged 60-74 years with no signs of periodontal pathology and patients with chronic generalized periodontitis of II-III severity. For the purpose of comparative characteristics of treatments performed using X-rays, reoparodontohrafiy, ultrasound osteometry bone jaws, carried out the analysis of the functional state of the endothelium of vascular endothelial growth factor (VEGF), levels of tumor necrosis factor (TNF) and kapilyaryzation of periodontal tissues to treat and dynamics . All patients were conducted generally accepted treatment of chronic generalized periodontitis , including closed curettage of periodontal pockets. 3 groups of patients on the background of basic therapy of periodontal handled tunnel revascularization with combined use of quercetin per os. It was established that with age in healthy elderly decrease in the number of functioning capillaries per unit area of fabric. The important role of the endothelium in providing adequate compensatory angiogenesis in aging shows the relationship of vascular endothelial growth factor levels of endothelium vazodylatation. Clinical determined that the combined use of revascularization tunnel and quercetin kapilar stabilization drug in treatment of elderly patients with generalized periodontitis stimulates metabolism in periodontal tissues, stabilizes the clinical and radiological picture considerably prolongs remission

СУЧАСНІ МЕТОДИ ВИЯВЛЕННЯ ЗБУДНИКА ТУБЕРКУЛЬОЗУ ТА ЙОГО МЕДИКАМЕНТОЗНОЇ ЧУТЛИВОСТІ ПРИ ТУБЕРКУЛЬОЗІ ОРГАНІВ ДИХАННЯ

SUMMARY. Sputum examination was performed on onesample using molecular genetic testing on Gene XpertMBT/RIF, sputum microscopy and culture plating fortuberculosis pathogen. Evaluation were performed on1449 sputum samples that were obtained in tuberculosisdispensary. The same tests were performed on 53patients from the hospital with MBT positive sputum.It was shown high molecular genetic test sensitivityfor MBT detection and evaluation of it resistance torifampicin. Similar results were obtained from culturedetection. Sputum microscopy examination was lessinformative for MBT detection.Key words: tuberculosis, methods of exciter exposure,medicinal sensitiveness.Проаналізовано результати молекулярно-генетичногодослідження системою Gene Xpert MBT/RIF1449 зразків харкотиння, взятих у осіб, що зверталисяв тубдиспансер. З одного зразка харкотиння одно-часно виконували також мікроскопію мазка і посіви наживильне середовище. Такий же аналіз проведено у53 стаціонарних хворих-бактеріовиділювачів. Вста-новлено високу чутливість молекулярно-генетичноготесту щодо виявлення мікобактерій туберкульозута їх стійкості до рифампіцину, яка була близькою дорезультатів культурального методу. Найменш ефек-тивною щодо виявлення мікобактерій була мікроскопіямазків харкотиння.Ключові слова: туберкульоз, методи виявленнязбудника, медикаментозна чутливість

Synthesis of Alkaline Earth Diazenides MAEN2 (MAE = Ca, Sr, Ba) by Controlled Thermal Decomposition of Azides under High Pressure

The alkaline earth diazenides MAEN2 with MAE = Ca, Sr and Ba were synthesized by a novel synthetic approach, namely, a controlled decomposition of the corresponding azides in a multianvil press at highpressure/ high-temperature conditions. The crystal structure of hitherto unknown calcium diazenide (space group I4/mmm (no. 139), a = 3.5747(6) Å, c = 5.9844(9) Å, Z = 2, wRp = 0.078) was solved and refined on the basis of powder X-ray diffraction data as well as that of SrN2 and BaN2. Accordingly, CaN2 is isotypic with SrN2 (space group I4/mmm (no. 139), a = 3.8054(2) Å, c = 6.8961(4) Å, Z = 2, wRp = 0.057) and the corresponding alkaline earth acetylenides (MAEC2) crystallizing in a tetragonally distorted NaCl structure type. In accordance with literature data, BaN2 adopts a more distorted structure in space group C2/c (no. 15) with a = 7.1608(4) Å, b = 4.3776(3) Å, c = 7.2188(4) Å, β = 104.9679(33)°, Z = 4 and wRp = 0.049). The N−N bond lengths of 1.202(4) Å in CaN2 (SrN2 1.239(4) Å, BaN2 1.23(2) Å) correspond well with a double-bonded dinitrogen unit confirming a diazenide ion [N2]2−. Temperature-dependent in situ powder X-ray diffractometry of the three alkaline earth diazenides resulted in formation of the corresponding subnitrides MAE2N (MAE = Ca, Sr, Ba) at higher temperatures. FTIR spectroscopy revealed a band at about 1380 cm−1 assigned to the N−N stretching vibration of the diazenide unit. Electronic structure calculations support the metallic character of alkaline earth diazenides

Association of IL4R single-nucleotide polymorphisms with rheumatoid nodules in African Americans with rheumatoid arthritis

Abstract Introduction To determine whether IL4R single-nucleotide polymorphisms (SNPs) rs1805010 (I50V) and rs1801275 (Q551R), which have been associated with disease severity in rheumatoid arthritis (RA) patients of European ancestry, relate to the presence of rheumatoid nodules and radiographic erosions in African Americans. Methods Two IL4R SNPs, rs1805010 and rs1801275, were genotyped in 749 patients from the Consortium for Longitudinal Evaluation of African-Americans with Early Rheumatoid Arthritis (CLEAR) registries. End points were rheumatoid nodules defined as present either by physical examination or by chest radiography and radiographic erosions (radiographs of hands/wrists and feet were scored using the modified Sharp/van der Heijde system). Statistical analyses were performed by using logistic regression modeling adjusted for confounding factors. Results Of the 749 patients with RA, 156 (20.8%) had rheumatoid nodules, with a mean age of 47.0 years, 84.6% female gender, and median disease duration of 1.9 years. Of the 461 patients with available radiographic data, 185 (40.1%) had erosions (score >0); their mean age was 46.7 years; 83.3% were women; and median disease duration was 1.5 years. Patients positive for HLA-DRB1 shared epitope (SE) and autoantibodies (rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP)) had a higher risk of developing rheumatoid nodules in the presence of the AA and AG alleles of rs1801275 (odds ratio (OR)adj = 8.08 (95% confidence interval (CI): 1.60-40.89), P = 0.01 and ORadj = 2.97 (95% CI, 1.08 to 8.17), P = 0.04, respectively). Likewise, patients positive for the HLA-DRB1 SE and RF alone had a higher risk of developing rheumatoid nodules in presence of the AA and AG alleles of rs1801275 (ORadj = 8.45 (95% CI, 1.57 to 45.44), P = 0.01, and ORadj = 3.57 (95% CI, 1.18 to 10.76), P = 0.02, respectively) and in the presence of AA allele of rs1805010 (ORadj = 4.52 (95% CI, 1.20 to 17.03), P = 0.03). No significant association was found between IL4R and radiographic erosions or disease susceptibility, although our statistical power was limited by relatively small numbers of cases and controls. Conclusions We found that IL4R SNPs, rs1801275 and rs1805010, are associated with rheumatoid nodules in autoantibody-positive African-American RA patients with at least one HLA-DRB1 allele encoding the SE. These findings highlight the need for analysis of genetic factors associated with clinical RA phenotypes in different racial/ethnic populations