Junctions of multiple quantum wires with different Luttinger parameters

Within the framework of boundary conformal field theory, we evaluate the conductance of stable fixed points of junctions of two and three quantum wires with different Luttinger parameters. For two wires, the physical properties are governed by a single effective Luttinger parameters for each of the charge and spin sectors. We present numerical density-matrix-renormalization-group calculations of the conductance of a junction of two chains of interacting spinless fermions with different interaction strengths, obtained using a recently developed method [Phys. Rev. Lett. 105, 226803 (2010)]. The numerical results show very good agreement with the analytical predictions. For three spinless wires, i.e., a Y junction, we analytically determine the full phase diagram, and compute all fixed-point conductances as a function of the three Luttinger parameters.Comment: 13 pages, 6 figure

18F-THK5351 PET imaging, neuropathology and clinical progression in a tau mouse model

Aims: Alzheimer’s disease (AD) and other associated dementias remain a consistent and unruly problem for the aging population and health. The neuropathology of AD is characterized by the extracellular deposition of beta-amyloid protein (Aβ) and the formation of intraneuronal neurofibrillary tangles (NFT) composed of hyperphosphorylated tau (ptau), along with neuroinflammation and neuronal loss that ultimately induces to noticeable cognitive impairments. Abnormal ptau leads to the formation of insoluble, beta-sheet rich amyloid aggregates in tauopathies such as AD. Positron emission tomography (PET) imaging is a promising avenue that may identify tau aggregates in vivo cross-sectionally and longitudinally in various dementia conditions. Methods: The goal of this study is to characterize the longitudinal assessment of the tau tracer 18F-THK5351 by in vivo tau PET imaging concomitantly to behavior and tau pathology by histology and biochemistry from 6 to 12 months of age in tau transgenic P301S mice, a mouse model of tauopathies. Results: Our results demonstrate an augmentation of overall gross brain tau pathology by in vivo PET imaging in P301S mice compared to age-matched wild-type (WT) animals accompanied by P301S-model associated pathological tau and phenotypic and behavioral deficits. Conclusions: This longitudinal study provides new insights on the relationship between imaging diagnostic tools, the in vivo neuropathological temporal pattern and the clinical signs observed in animal models of AD that could benefit early disease diagnosis.This work was partially funded by Department of Defense Peer Reviewed Alzheimer’s Research Program Convergence Science. Research Award grant AZ160106 and Alzheimer’s Association New Investigator Research Grant NIRG-394284 to IMG. Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Extensive Accumulation of Misfolded Protein Aggregates During Natural Aging and Senescence

Accumulation of misfolded protein aggregates is a hallmark event in many age-related protein misfolding disorders, including some of the most prevalent and insidious neurodegenerative diseases. Misfolded protein aggregates produce progressive cell damage, organ dysfunction, and clinical changes, which are common also in natural aging. Thus, we hypothesized that aging is associated to the widespread and progressive misfolding and aggregation of many proteins in various tissues. In this study, we analyzed whether proteins misfold, aggregate, and accumulate during normal aging in three different biological systems, namely senescent cells

Detection of prions in blood from patients with variant Creutzfeldt-Jakob disease

Prions can be detected in blood from patients with variant Creutzfeldt-Jakob disease with high sensitivity and specificity.</jats:p

MatterGen: a generative model for inorganic materials design

The design of functional materials with desired properties is essential in driving technological advances in areas like energy storage, catalysis, and carbon capture. Generative models provide a new paradigm for materials design by directly generating entirely novel materials given desired property constraints. Despite recent progress, current generative models have low success rate in proposing stable crystals, or can only satisfy a very limited set of property constraints. Here, we present MatterGen, a model that generates stable, diverse inorganic materials across the periodic table and can further be fine-tuned to steer the generation towards a broad range of property constraints. To enable this, we introduce a new diffusion-based generative process that produces crystalline structures by gradually refining atom types, coordinates, and the periodic lattice. We further introduce adapter modules to enable fine-tuning towards any given property constraints with a labeled dataset. Compared to prior generative models, structures produced by MatterGen are more than twice as likely to be novel and stable, and more than 15 times closer to the local energy minimum. After fine-tuning, MatterGen successfully generates stable, novel materials with desired chemistry, symmetry, as well as mechanical, electronic and magnetic properties. Finally, we demonstrate multi-property materials design capabilities by proposing structures that have both high magnetic density and a chemical composition with low supply-chain risk. We believe that the quality of generated materials and the breadth of MatterGen's capabilities represent a major advancement towards creating a universal generative model for materials design.Comment: 13 pages main text, 35 pages supplementary informatio

TAMEP are brain tumor parenchymal cells controlling neoplastic angiogenesis and progression

Aggressive brain tumors like glioblastoma depend on support by their local environment and subsets of tumor parenchymal cells may promote specific phases of disease progression. We investigated the glioblastoma microenvironment with transgenic lineage-tracing models, intravital imaging, single-cell transcriptomics, immunofluorescence analysis as well as histopathology and characterized a previously unacknowledged population of tumor-associated cells with a myeloid-like expression profile (TAMEP) that transiently appeared during glioblastoma growth. TAMEP of mice and humans were identified with specific markers. Notably, TAMEP did not derive from microglia or peripheral monocytes but were generated by a fraction of CNS-resident, SOX2-positive progenitors. Abrogation of this progenitor cell population, by conditional Sox2-knockout, drastically reduced glioblastoma vascularization and size. Hence, TAMEP emerge as a tumor parenchymal component with a strong impact on glioblastoma progression

OBTENÇÃO DE PADRÃO ANALÍTICO DE RETINOL A PARTIR DE FÍGADO BOVINO POR CROMATOGRAFIA LÍQUIDA DE ALTA EFICIÊNCIA

Para a quantificação de substâncias de interesse, por Cromatografia Líquida de Alta Eficiência (CLAE), é necessário a obtenção de padrões analíticos confiáveis. Porém a aquisição destes padrões, com certificado de garantia, quase sempre depende de importação e apresenta custos elevados. As substâncias adquiridas ainda podem sofrer degradação, devido ao longo tempo de transporte e as condições inadequadas de armazenamento. A vitamina A ou retinol (C20H30O) é um álcool lipossolúvel encontrada apenas em fontes animais, em especial em áreas de armazenamento como o fígado ou associadas a gorduras como a do leite. O presente trabalho teve como objetivo isolar e quantificar retinol com alto teor de pureza a partir de fígado bovino para posterior utilização como padrão analítico. Após extração e hidrólise o retinol foi purificado do extrato de fígado por CLAE. A confirmação qualitativa foi realizada por Espectrometria de Massas de Alta Resolução (ESI-Q-TOF). Desta maneira foi possível a obtenção de retinol com 99% de pureza, demonstrando que a técnica utilizada possibilitou a preparação de padrão analítico para utilização em análises de CLAE. O processo reduz o risco de degradação da substância por condições inadequadas de transporte e manuseio, além de minimizar os custos dos procedimentos analíticos.

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO