Antiferromagnetic domain walls in lightly doped layered cuprates

Recent ESR data shows rotation of the antiferromagnetic (AF) easy axis in lightly doped layered cuprates upon lowering the temperature. We account for the ESR data and show that it has significant implications on spin and charge ordering according to the following scenario: In the high temperature phase AF domain walls coincide with (110) twin boundaries of an orthorhombic phase. A magnetic field leads to annihilation of neighboring domain walls resulting in antiphase boundaries. The latter are spin carriers, form ferromagnetic lines and may become charged in the doped system. However, hole ordering at low temperatures favors the (100) orientation, inducing a pi/4 rotation in the AF easy axis. The latter phase has twin boundaries and AF domain walls in (100) planes.Comment: 4 pages, 3 figures (1 eps). v2: no change in content, Tex shadow problem cleare

Exchange Anisotropy in Epitaxial and Polycrystalline NiO/NiFe Bilayers

(001) oriented NiO/NiFe bilayers were grown on single crystal MgO (001) substrates by ion beam sputtering in order to determine the effect that the crystalline orientation of the NiO antiferromagnetic layer has on the magnetization curve of the NiFe ferromagnetic layer. Simple models predict no exchange anisotropy for the (001)-oriented surface, which in its bulk termination is magnetically compensated. Nonetheless exchange anisotropy is present in the epitaxial films, although it is approximately half as large as in polycrystalline films that were grown simultaneously. Experiments show that differences in exchange field and coercivity between polycrystalline and epitaxial NiFe/NiO bilayers couples arise due to variations in induced surface anisotropy and not from differences in the degree of compensation of the terminating NiO plane. Implications of these observations for models of induced exchange anisotropy in NiO/NiFe bilayer couples will be discussed.Comment: 23 pages in RevTex format, submitted to Phys Rev B

Spermidine reduces neuroinflammation and soluble amyloid beta in an Alzheimer’s disease mouse model

BACKGROUND: Deposition of amyloid beta (Aß) and hyperphosphorylated tau along with glial cell-mediated neuroinflammation are prominent pathogenic hallmarks of Alzheimer's disease (AD). In recent years, impairment of autophagy has been identified as another important feature contributing to AD progression. Therefore, the potential of the autophagy activator spermidine, a small body-endogenous polyamine often used as dietary supplement, was assessed on Aß pathology and glial cell-mediated neuroinflammation. RESULTS: Oral treatment of the amyloid prone AD-like APPPS1 mice with spermidine reduced neurotoxic soluble Aß and decreased AD-associated neuroinflammation. Mechanistically, single nuclei sequencing revealed AD-associated microglia to be the main target of spermidine. This microglia population was characterized by increased AXL levels and expression of genes implicated in cell migration and phagocytosis. A subsequent proteome analysis of isolated microglia confirmed the anti-inflammatory and cytoskeletal effects of spermidine in APPPS1 mice. In primary microglia and astrocytes, spermidine-induced autophagy subsequently affected TLR3- and TLR4-mediated inflammatory processes, phagocytosis of Aß and motility. Interestingly, spermidine regulated the neuroinflammatory response of microglia beyond transcriptional control by interfering with the assembly of the inflammasome. CONCLUSIONS: Our data highlight that the autophagy activator spermidine holds the potential to enhance Aß degradation and to counteract glia-mediated neuroinflammation in AD pathology

Temporal omics analysis in Syrian hamsters unravel cellular effector responses to moderate COVID-19

In COVID-19, immune responses are key in determining disease severity. However, cellular mechanisms at the onset of inflammatory lung injury in SARS-CoV-2 infection, particularly involving endothelial cells, remain ill-defined. Using Syrian hamsters as a model for moderate COVID-19, we conduct a detailed longitudinal analysis of systemic and pulmonary cellular responses, and corroborate it with datasets from COVID-19 patients. Monocyte-derived macrophages in lungs exert the earliest and strongest transcriptional response to infection, including induction of pro-inflammatory genes, while epithelial cells show weak alterations. Without evidence for productive infection, endothelial cells react, depending on cell subtypes, by strong and early expression of anti-viral, pro-inflammatory, and T cell recruiting genes. Recruitment of cytotoxic T cells as well as emergence of IgM antibodies precede viral clearance at day 5 post infection. Investigating SARS-CoV-2 infected Syrian hamsters thus identifies cell type-specific effector functions, providing detailed insights into pathomechanisms of COVID-19 and informing therapeutic strategies

Generation of a non-small cell lung cancer transcriptome microarray

<p>Abstract</p> <p>Background</p> <p>Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. At present no reliable biomarkers are available to guide the management of this condition. Microarray technology may allow appropriate biomarkers to be identified but present platforms are lacking disease focus and are thus likely to miss potentially vital information contained in patient tissue samples.</p> <p>Methods</p> <p>A combination of large-scale in-house sequencing, gene expression profiling and public sequence and gene expression data mining were used to characterise the transcriptome of NSCLC and the data used to generate a disease-focused microarray – the Lung Cancer DSA research tool.</p> <p>Results</p> <p>Built on the Affymetrix GeneChip platform, the Lung Cancer DSA research tool allows for interrogation of ~60,000 transcripts relevant to Lung Cancer, tens of thousands of which are unavailable on leading commercial microarrays.</p> <p>Conclusion</p> <p>We have developed the first high-density disease specific transcriptome microarray. We present the array design process and the results of experiments carried out to demonstrate the array's utility. This approach serves as a template for the development of other disease transcriptome microarrays, including non-neoplastic diseases.</p

Теофиллин и его производные

Теофиллин является по химической структуре 1,3-диметил ксантином, близким к кофеину и теобромину