191 research outputs found

    Polarization-selective grating mirrors used in the generation of radial polarization

    Get PDF
    Two novel methods to control the polarization of laser radiation are presented. The discrimination between different polarization distributions isperformed with a corrugation grating in the top high-index layer of a multilayer mirror, which couples the undesired polarization into a lossy waveguidemode of the multilayer. The generation of radially polarized radiation in a laser resonator is presented as a practical verification of the principl

    Duty cycle tolerant binary gratings for fabricable short period phase masks

    Get PDF
    Wavelength scale 1D binary gratings of rectangular corrugation profile are often used as diffractive elements acting on incident free space waves under different incidence angle, wavelength and polarization. Their optical function is best understood by considering the interplay of the grating modes propagating up and down the periodic walls and slits of the segmented structure. The interference conditions between modes depend on the difference between the effective index of the interfering modes and on their relative amplitude. This difference and relative amplitude depend critically on the ratio between the wall and slit widths which is difficult to control technologically. The condition for a wide tolerance of the effective index difference and for a balanced mode excitation on the wall/slit ratio is found analytically and once for all for a wide class of 1D gratings. It is also found that TE interference elements may exhibit a very wide wall/slit ratio tolerance domain

    Spatially and polarization resolved plasmon mediated transmission through continuous metal films

    Full text link
    The experimental demonstration and characterization is made of the plasmon-mediated resonant transmission through an embedded undulated continuous thin metal film under normal incidence. 1D undulations are shown to enable a spatially resolved polarisation filtering whereas 2D undulations lead to spatially resolved, polarization independent transmission. Whereas the needed submicron microstructure lends itself in principle to CD-like low-cost mass replication by means of injection moulding and embossing, the present paper demonstrates the expected transmission effects on experimental models based on metal-coated photoresist gratings. The spectral and angular dependence in the neighbourhood of resonance are investigated and the question of the excess losses exhibited by surface plasmons is discusse

    Diarrhea and fever as risk factors for anemia among children under age five living in urban slum areas of Indonesia

    Get PDF
    SummaryObjectivesTo characterize diarrhea and fever as risk factors for anemia among children in developing countries.MethodsWe characterized risk factors for anemia in a sample of 32873 children, aged 6–59 months, from poor families in urban slum areas of Indonesia from 2000 to 2003.ResultsThe prevalence of anemia was 58.7%. In separate multivariate models, after adjusting for age, sex, stunting, maternal age and education, and weekly per capita household expenditure, current diarrhea (OR 1.20, 95% CI 1.07–1.35, p=0.002), current fever (OR 1.44, 95% CI 1.18–1.75, p<0.0001), and a history of diarrhea in the previous seven days (OR 1.12, 95% CI 1.03–1.23, p=0.024) were associated with an increased risk of anemia.ConclusionsDiarrhea and fever are important risk factors for anemia among young children living in urban slum communities in Indonesia

    DNA mismatch repair activity of MutLα is regulated by CK2-dependent phosphorylation of MLH1 (S477)

    Get PDF
    MutLα, a heterodimer consisting of MLH1 and PMS2, is a key player of DNA mismatch repair (MMR), yet little is known about its regulation. In this study, we used mass spectrometry to identify phosphorylated residues within MLH1 and PMS2. The most frequently detected phosphorylated amino acid was serine 477 of MLH1. Pharmacological treatment indicates‎ that Casein kinase II (CK2) could be responsible for the phosphorylation of MLH1 at serine 477 in vivo. In vitro kinase assay verified MLH1 as a substrate of CK2. Most importantly, using in vitro MMR assay we could demonstrate that p-MLH1S477 lost MMR activity. Moreover, we found that levels of p-MLH1S477 varied during the cell cycle. In summary, we identified that phosphorylation of MLH1 by CK2 at amino acid position 477 can switch off MMR activity in vitro. Since CK2 is overexpressed in many tumors and is able to inactivate MMR, the new mechanism here described could have an important impact on tumors overactive in CK2.Fil: Weßbecher, Isabel M.. Goethe Universitat Frankfurt; AlemaniaFil: Hinrichsen, Inga. Goethe Universitat Frankfurt; AlemaniaFil: Funke, Sebastian. Klinikum Der Johannes-gutenberg-universität Und Fachbereich Medizin; AlemaniaFil: Oellerich, Thomas. Goethe Universitat Frankfurt; AlemaniaFil: Plotz, Guido. Goethe Universitat Frankfurt; AlemaniaFil: Zeuzem, Stefan. Goethe Universitat Frankfurt; AlemaniaFil: Grus, Franz H.. Klinikum Der Johannes-gutenberg-universität Und Fachbereich Medizin; AlemaniaFil: Biondi, Ricardo Miguel. Goethe Universitat Frankfurt; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Brieger, Angela. Goethe Universitat Frankfurt; Alemani
    • …
    corecore