373 research outputs found
Cancellation of probe effects in measurements of spin polarized momentum density by electron positron annihilation
Measurements of the two dimensional angular correlation of the
electron-positron annihilation radiation have been done in the past to detect
the momentum spin density and the Fermi surface. We point out that the momentum
spin density and the Fermi Surface of ferromagnetic metals can be revealed
within great detail owing to the large cancellation of the electron-positron
matrix elements which in paramagnetic multiatomic systems plague the
interpretation of the experiments. We prove our conjecture by calculating the
momentum spin density and the Fermi surface of the half metal CrO2, who has
received large attention due to its possible applications as spintronics
material
Positronium reflection and positronium beams
Specular reflection of positronium, Ps was observed and that there is adequate intensity at higher energies to make further study worthwhile was established. The scattering appears to be restricted to the outermost surface with a mean free path of (0.75 + or - 0.15)A for Ps in LiF(100). With a greater intensity Ps beam one should see higher order diffraction beams as the result of the periodicity of the surface. Ps diffraction thus offers the possibility of being a novel and valuable probe to study the outermost surface and to study adsorbants on it. Two methods for producing Ps beams are described
Overlap of Functional Gastrointestinal Disorders: Common Mechanisms of Pathogenesis as a Key to Rational Therapy
Aim: to review the common risk factors and links in the pathogenesis of functional gastrointestinal disorders (FGID) to optimize therapy of patients with a combination of multiple FGID.Key points. FGID occurs in more than 40 % of people globally, mainly affecting the working-age population in young and middle-aged subjects. At the same time, more than 30 % of patients have a combination of 2 or more functional gastrointestinal (GI) disorders i.e. overlap syndrome. Common links in the pathogenesis of FGID include disorders of gut-brain interaction, visceral hypersensitivity, changes in intestinal microbiota, overproduction of proinflammatory cytokines, impaired epithelial permeability and motor activity of the gastrointestinal tract. The combination of FGID in various gastrointestinal segments is associated with more pronounced clinical symptoms (mutual burden syndrome). Common risk factors and pathogenetic links of the functional disorders enables reducing the number of prescribed medications when several FGIDs overlap in one patient, which also increases adherence to therapy. Treatment of FGID includes adjustment of risk factors and drug therapy. As a pathogenetically justified pharmacotherapy of overlap syndrome, Kolofort, highly diluted antibodies to TNF-Ξ±, histamine and brain-specific protein S-100, is of interest.Conclusion. Kolofort has demonstrated high efficacy and safety including among patients with overlap FGID enabling to consider it as the treatment of choice in these patients
Detecting, Quantifying, and Discriminating the Mechanism of Mosaic Chromosomal Aneuploidies Using MAD-seq
Current approaches to detect and characterize mosaic chromosomal aneuploidy are limited by sensitivity, efficiency, cost, or the need to culture cells. We describe the mosaic aneuploidy detection by massively parallel sequencing (MAD-seq) capture assay and the MADSEQ analytical approach that allow low
Full potential LAPW calculation of electron momentum density and related properties of Li
Electron momentum density and Compton profiles in Lithium along , and directions are calculated using Full-Potential Linear
Augmented Plane Wave basis within generalized gradient approximation. The
profiles have been corrected for correlations with Lam-Platzman formulation
using self-consistent charge density. The first and second derivatives of
Compton profiles are studied to investigate the Fermi surface breaks. Decent
agreement is observed between recent experimental and our calculated values.
Our values for the derivatives are found to be in better agreement with
experiments than earlier theoretical results. Two-photon momentum density and
one- and two-dimensional angular correlation of positron annihilation radiation
are also calculated within the same formalism and including the
electron-positron enhancement factor.Comment: 11 pages, 7 figures TO appear in Physical Review
Towards an understanding of hole superconductivity
From the very beginning K. Alex M\"uller emphasized that the materials he and
George Bednorz discovered in 1986 were superconductors. Here I would
like to share with him and others what I believe to be key reason for why
high cuprates as well as all other superconductors are hole
superconductors, which I only came to understand a few months ago. This paper
is dedicated to Alex M\"uller on the occasion of his 90th birthday.Comment: Dedicated to Alex M\"uller on the Occasion of his 90th Birthday.
arXiv admin note: text overlap with arXiv:1703.0977
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Genomic Profiling of Childhood Tumor Patient-Derived Xenograft Models to Enable Rational Clinical Trial Design.
Accelerating cures for children with cancer remains an immediate challenge as a result of extensive oncogenic heterogeneity between and within histologies, distinct molecular mechanisms evolving between diagnosis and relapsed disease, and limited therapeutic options. To systematically prioritize and rationally test novel agents in preclinical murine models, researchers within the Pediatric Preclinical Testing Consortium are continuously developing patient-derived xenografts (PDXs)-many of which are refractory to current standard-of-care treatments-from high-risk childhood cancers. Here, we genomically characterize 261 PDX models from 37 unique pediatric cancers; demonstrate faithful recapitulation of histologies and subtypes; and refine our understanding of relapsed disease. In addition, we use expression signatures to classify tumors for TP53 and NF1 pathway inactivation. We anticipate that these data will serve as a resource for pediatric oncology drug development and will guide rational clinical trial design for children with cancer
Why choo-choo is better than train:The role of register-specific words in early vocabulary growth
Evaluation of the influence of climatic factors on work of air lines with 110 kV stress
In work the influence of weather conditions on VL-110 kV is considered. Recommendations are given for installing the most appropriate protections to reduce the impact of negative factors. A correlation was established between the failure flow of the 110 kV overhead line and climatic factors.Π ΡΠ°Π±ΠΎΡΠ΅ ΡΠ°ΡΡΠΌΠΎΡΡΠ΅Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΠΏΠΎΠ³ΠΎΠ΄Π½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΠΉ Π½Π° ΠΠ-110 ΠΊΠ. ΠΠ°Π½Ρ ΡΠ΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°ΡΠΈΠΈ ΠΏΠΎ ΡΡΡΠ°Π½ΠΎΠ²ΠΊΠ΅ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΠΏΡΠΈΠ΅ΠΌΠ»Π΅ΠΌΡΡ
Π·Π°ΡΠΈΡ Π΄Π»Ρ ΡΠΌΠ΅Π½ΡΡΠ΅Π½ΠΈΡ Π²ΠΎΠ·Π΄Π΅ΠΉΡΡΠ²ΠΈΡ Π½Π΅Π³Π°ΡΠΈΠ²Π½ΡΡ
ΡΠ°ΠΊΡΠΎΡΠΎΠ². ΠΡΠ»Π° ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π° ΠΊΠΎΡΡΠ΅Π»ΡΡΠΈΠΎΠ½Π½Π°Ρ ΡΠ²ΡΠ·Ρ ΠΌΠ΅ΠΆΠ΄Ρ ΠΏΠΎΡΠΎΠΊΠΎΠΌ ΠΎΡΠΊΠ°Π·ΠΎΠ² ΠΠ-110 ΠΊΠ ΠΈ ΠΊΠ»ΠΈΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΡΠ°ΠΊΡΠΎΡΠ°ΠΌΠΈ
Comparing different models of the development of verb inflection in early child Spanish
How children acquire knowledge of verb inflection is a long-standing question in language acquisition research. In the present study, we test the predictions of some current constructivist and generativist accounts of the development of verb inflection by focusing on data from two Spanish-speaking children between the ages of 2;0 and 2;6. The constructivist claim that children's early knowledge of verb inflection is only partially productive is tested by comparing the average number of different inflections per verb in matched samples of child and adult speech. The generativist claim that children's early use of verb inflection is essentially error-free is tested by investigating the rate at which the children made subjectverb agreement errors in different parts of the present tense paradigm. Our results show: 1) that, although even adults ' use of verb inflection in Spanish tends to look somewhat lexically restricted, both children's use of verb inflection was significantly less flexible than that of their caregivers, and 2) that, although the rate at which the two children produced subjectverb agreement errors in their speech was very low, this overall error rate hid a consistent pattern of error in which error rates were substantially higher in low frequency than in high frequency contexts, and substantially higher for low frequency than for high frequency verbs. These results undermine the claim that children's use of verb inflection is fully productive from the earliest observable stages, and are consistent with the constructivist claim that knowledge of verb inflection develops only gradually
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