Wyler L.,University of Zurich |
Napoli C.U.,University of Basel |
Ingold B.,University of Zurich |
Sulser T.,University of Zurich |
And 3 more authors.
British Journal of Cancer | Year: 2014
Background:The mechanisms of brain metastasis in renal cell cancer (RCC) patients are poorly understood. Chemokine and chemokine receptor expression may contribute to the predilection of RCC for brain metastasis by recruitment of monocytes/macrophages and by control or induction of vascular permeability of the blood-brain barrier.Methods:Frequency and patterns of brain metastasis were determined in 246 patients with metastatic RCC at autopsy. Expression of CXCR4, CCL7 (MCP-3), CCR2 and CD68 + tumour-associated macrophages (TAMs) were analysed in a separate series of 333 primary RCC and in 48 brain metastases using immunohistochemistry.Results:Fifteen percent of 246 patients with metastasising RCC had brain metastasis. High CXCR4 expression levels were found in primary RCC and brain metastases (85.7% and 91.7%, respectively). CCR2 (52.1%) and CCL7 expression (75%) in cancer cells of brain metastases was more frequent compared with primary tumours (15.5% and 16.7%, respectively; P<0.0001 each). The density of CD68 + TAMs was similar in primary RCC and brain metastases. However, TAMs were more frequently CCR2-positive in brain metastases than in primary RCC (P<0.001).Conclusion:Our data demonstrate that the monocyte-specific chemokine CCL7 and its receptor CCR2 are expressed in tumour cells of RCC. We conclude that monocyte recruitment by CCR2 contributes to brain metastasis of RCC. © 2014 Cancer Research UK.
Mao J.,Pennsylvania State University |
Ren X.,Pennsylvania State University |
Ren X.,University of Miami |
Chen S.,Pennsylvania State University |
And 10 more authors.
Atmospheric Environment | Year: 2010
Both similarities and differences in summertime atmospheric photochemical oxidation appear in the comparison of four field studies: TEXAQS2000 (Houston, 2000), NYC2001 (New York City, 2001), MCMA2003 (Mexico City, 2003), and TRAMP2006 (Houston, 2006). The compared photochemical indicators are OH and HO2 abundances, OH reactivity (the inverse of the OH lifetime), HOx budget, OH chain length (ratio of OH cycling to OH loss), calculated ozone production, and ozone sensitivity. In terms of photochemical activity, Houston is much more like Mexico City than New York City. These relationships result from the ratio of volatile organic compounds (VOCs) to nitrogen oxides (NOx), which are comparable in Houston and Mexico City, but much lower in New York City. Compared to New York City, Houston and Mexico City also have higher levels of OH and HO2, longer OH chain lengths, a smaller contribution of reactions with NOx to the OH reactivity, and NOx-sensitivity for ozone production during the day. In all four studies, the photolysis of nitrous acid (HONO) and formaldehyde (HCHO) are significant, if not dominant, HOx sources. A problematic result in all four studies is the greater OH production than OH loss during morning rush hour, even though OH production and loss are expected to always be in balance because of the short OH lifetime. The cause of this discrepancy is not understood, but may be related to the under-predicted HO2 in high NOx conditions, which could have implications for ozone production. Three photochemical indicators show particularly high photochemical activity in Houston during the TRAMP2006 study: the long portion of the day for which ozone production was NOx-sensitive, the calculated ozone production rate that was second only to Mexico City's, and the OH chain length that was twice that of any other location. These results on photochemical activity provide additional support for regulatory actions to reduce reactive VOCs in Houston in order to reduce ozone and other pollutants. © 2009 Elsevier Ltd.
Mgbemere H.,University of Lagos |
Mgbemere H.,TU Hamburg - Harburg |
Schneider G.,TU Hamburg - Harburg |
Hoelzel M.,Technical University Mu Nchen |
And 2 more authors.
Journal of Applied Crystallography | Year: 2016
A neutron diffraction study of (KxNa1-x)NbO3-based ceramics has been carried out from 5 K to high temperatures well above the Curie temperature. The diffraction data were analysed using Rietveld refinement. For pure KNN samples, especially at the Na-rich side of the phase diagram, the lowtemperature structure of simple rhombohedral symmetry changes to a highly complex monoclinic structure at a higher temperature. Chemical analysis on the samples showed good agreement of the expected and actual compositions. Trigonal, monoclinic, orthorhombic, tetragonal and cubic phase models as well as two-phase mixtures are observed depending on the temperature of measurement. Space groups R3c, P1m1, P11m, Amm2, P4mm, Pm3m and their combinations are used to refine the trigonal, monoclinic, orthorhombic, tetragonal, cubic and mixed phases, respectively. For the (K0.48Na0.48Li0.04)- (Nb0.86Ta0.1Sb0.04)O3 sample at temperatures between 5 and 300 K, the monoclinic P11m space group gives the best refinement fit. For the (K0.17Na0.83)NbO3 sample, a two-phase refinement using the trigonal R3c and monoclinic Pm space groups gave the best fit at 300 K, while at 5-150 K the trigonal R3c space group gives the best fit. The understanding of the structure of these lead-free ceramics will help in the optimization of their piezoelectric properties. © 2016 International Union of Crystallography.
Vanderelst D.,University of Antwerp |
de Mey F.,University of Antwerp |
Peremans H.,University of Antwerp |
Geipel I.,University of Ulm |
And 3 more authors.
PLoS ONE | Year: 2010
Background:Many bats vocalizing through their nose carry a prominent noseleaf that is involved in shaping the emission beam of these animals. To our knowledge, the exact role of these appendages has not been thoroughly investigated as for no single species both the hearing and the emission spatial sensitivities have been obtained. In this paper, we set out to evaluate the complete spatial sensitivity of two species of New World leaf-nosed bats: Micronycteris microtis and Phyllostomus discolor. From an ecological point of view, these species are interesting as they belong to the same family (Phyllostomidae) and their noseleaves are morphologically similar. They differ vastly in the niche they occupy. Comparing these species allows us to relate differences in function of the noseleaf to the ecological background of bat species. Methodology/Principal Findings:We simulate the spatial sensitivity of both the hearing and the emission subsystems of two species, M. microtis and P. discolor. This technique allows us to evaluate the respective roles played by the noseleaf in the echolocation system of these species. We find that the noseleaf of M. microtis focuses the radiated energy better and yields better control over the emission beam. Conclusions:From the evidence presented we conclude that the noseleaves serve quantitatively different functions for different bats. The main function of the noseleaf is to serve as an energy focusing mechanism that increases the difference between the reflected energy from objects in the focal area and objects in the periphery. However, despite the gross morphological similarities between the noseleaves of the two Phyllostomid species they focus the energy to a different extent, a capability that can be linked to the different ecological niches occupied by the two species. © 2010 Vanderelst et al.
Busch P.,Julich Research Center |
Rauscher M.,Max Planck Institute for Metals Research |
Rauscher M.,University of Stuttgart |
Moulin J.-F.,Helmholtz Center Geesthacht |
Muller-Buschbaum P.,Technical University Mu Nchen
Journal of Applied Crystallography | Year: 2011
The powder-like orientation of lamellar domains in thin films of the diblock copolymer polystyrene-block-poly(methyl methacrylate) is investigated using grazing-incidence small-angle X-ray scattering (GISAXS) and grazing-incidence small-angle neutron scattering (GISANS). Conventional monochromatic GISANS and GISAXS measurements are compared with neutron time-of-flight GISANS. For angles of incidence and exit larger than the critical angle of total external reflection of the polymer, Debye-Scherrer rings are observed. The position of the Debye-Scherrer rings is described quantitatively based on a reduced version of the distorted-wave Born approximation. A strong distortion of the ring shape is caused by refraction and reflections from the film interfaces. Close to the critical angle, the ring shape collapses into a banana shape. © 2011 International Union of Crystallography Printed in Singapore - all rights reserved.