Space-variant polarization conversion with artificial birefringent metallic elements.

We present an artificial birefringent space-variant polarization converter for the near infrared, λ = 1550 nm. Each hollow waveguide has a rectangular shape with lateral dimensions of 1550 nm in the x-direction and 1034 nm as the largest length in the y-direction. The whole device consists of approximately 2000 × 2500 hollow waveguides realized in a 2-µm-thick gold structure.

Fibronectin Adherent Cell Populations Derived From Avascular and Vascular Regions of the Meniscus Have Enhanced Clonogenicity and Differentiation Potential Under Physioxia.

The meniscus is composed of an avascular inner region and vascular outer region. The vascular region has been shown to contain a progenitor population with multilineage differentiation capacity. Strategies facilitating the isolation and propagation of these progenitors can be used to develop cell-based meniscal therapies.

Ecophysiological and Cell Biological Traits of Benthic Diatoms From Coastal Wetlands of the Southern Baltic Sea.

The German Baltic Sea coastline is characterized by sea-land transitions zones, specifically coastal peatlands. Such transition zones exhibit highly fluctuating environmental parameters and dynamic gradients that affect physiological processes of inhabiting organisms such as microphytobenthic communities. In the present study four representative and abundant benthic diatom strains [s, , sp.

'Just Drive': An Employee-Based Intervention to Reduce Distracted Driving.

Distracted driving is a major danger on today's roadways. Employers play a critical role in developing distracted driving policies and promoting a culture of workplace driving safety. The purpose of this study was to evaluate the effectiveness of an in-person work-based class to reduce distracted driving in participating employees.

Self-imaging of tailored vortex pulse arrays and spectral Gouy rotation echoes.

Self-imaging of femtosecond pulses with orbital angular momentum is studied in spectral domain by illuminating the orthogonal arrays of spiral gratings. Spectral Gouy rotation, i.e.

Development of a curriculum and roadside screening tool for Law enforcement identification of medical impairment in aging drivers.

Background: An estimated one in five drivers will be over 65 by 2030. Compared with their younger counterparts, older adults are more likely to experience health and functional impairments, including cognitive dysfunction, which may interfere with their ability to drive safely. Law enforcement officers, as part of the public safety community, need help in developing the necessary skills to identify and manage these medically affected drivers.

Refractive-diffractive dispersion compensation for optical vortex beams with ultrashort pulse durations.

Wave fields, which are described mathematically by higher order Bessel functions, carry an orbital angular momentum and thus represent particular types of optical vortex beams with helical wavefronts. For the generation of such vortex beams, one may use, for instance, diffractive spiral axicons. Diffraction, however, leads invariably to strong dispersion, which is detrimental for ultrashort pulses since it leads to severe pulse broadening.

Profiling of low molecular weight proteins in plasma from locally irradiated individuals.

In studies reported in the 1960s and since, blood plasma from radiation-exposed individuals has been shown to induce chromosome damage when transferred into lymphocyte cultures of non-irradiated persons. This effect has been described to occur via clastogenic factors, whose nature is still mostly unknown. We have previously examined clastogenic factors from irradiated individuals by looking at plasma-induced DNA damage in reporter cells.

Diffraction theory for azimuthally structured Fresnel zone plate.

A conventional Fresnel zone plate (FZP) consists of concentric rings with an alternating binary transmission of zero and one. In an azimuthally structured Fresnel zone plate (aFZP), the light transmission of the transparent zones is modulated in the azimuthal direction, too. The resulting structure is of interest for extreme ultraviolet and x-ray imaging, in particular, because of its improved mechanical stability as compared to the simple ring structure of an FZP.

Few-cycle high-contrast vortex pulses.

Few-cycle high-contrast vortex beams with pulse durations around 8 fs were generated from a Ti:sapphire laser oscillator with a single diffractive-refractive component. Angular and temporal pulse properties were characterized with an advanced time-wavefront sensor. The temporal transfer indicates a fairly complete self-compensation.

Highly precise micro-retroreflector array fabricated by the LIGA process and its application as tapped delay line filter.

We report on the fabrication of a one-dimensional micro-retroreflector array with a pitch of 100 μm. The array was fabricated by x-ray lithography and the lithographie, galvanik und abformung (LIGA) process in a 1 mm thick poly(methyl methacrylate) (PMMA) layer and subsequently covered with Au. The area of the array is 1 mm×10 mm.

Search for clastogenic factors in the plasma of locally irradiated individuals.

In studies reported in the 1960s and in several investigations since, plasma from irradiated individuals was shown to induce chromosomal aberrations when transferred into normal blood cultures. In the present study, the aim was to investigate the occurrence of these clastogenic factors (CF) using markers representing DNA damage produced in reporter lymphocytes that are treated with plasma from locally exposed individuals. Blood plasma was obtained from clinical patients with benign conditions before and after they had received radiation to small treatment volumes.

Influence of low dose irradiation on differentiation, maturation and T-cell activation of human dendritic cells.

Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment.

Plasmonic multimode waveguides with transversely structured core.

We analyze the propagation of surface plasmons in metallic multimode waveguides that consist of alternating stripes of different metals in the transverse direction and that are homogeneous in the longitudinal direction. The purpose of structuring the waveguide in the transverse direction is to take advantage of the different attenuation and propagation constants for different metals. Here, in particular, alternating stripes of Ag and Au are considered.

Analysis of the self-imaging effect in plasmonic multimode waveguides.

We present studies on the propagation of plasmon waves in metallic multimode waveguides surrounded by a dielectric medium. The permittivity of the metal was determined by a Drude model. The propagation was simulated by the method of lines.

Allogeneic non-adherent bone marrow cells facilitate hematopoietic recovery but do not lead to allogeneic engraftment.

Background: Non adherent bone marrow derived cells (NA-BMCs) have recently been described to give rise to multiple mesenchymal phenotypes and have an impact in tissue regeneration. Therefore, the effects of murine bone marrow derived NA-BMCs were investigated with regard to engraftment capacities in allogeneic and syngeneic stem cell transplantation using transgenic, human CD4(+), murine CD4(-/-), HLA-DR3(+) mice.

Methodology/principal Findings: Bone marrow cells were harvested from C57Bl/6 and Balb/c wild-type mice, expanded to NA-BMCs for 4 days and characterized by flow cytometry before transplantation in lethally irradiated recipient mice.

Optical wave fields with lateral and longitudinal periodicity.

The propagation of stationary wave fields that exhibit simultaneously lateral and longitudinal periodicity is investigated. As a model, we use a Fabry-Perot resonator with periodically structured mirrors under monochromatic plane wave illumination. The resonator leads to a longitudinal periodicity, the grating mirrors to a lateral periodicity.

Additive effects of 5-aza-2'-deoxycytidine and irradiation on clonogenic survival of human medulloblastoma cell lines.

Background And Purpose: In recent years, epigenetic modulators were introduced into tumor therapy. Here, the authors investigated the antitumor effect of 5-aza-2'-deoxycytidine-(5-aza-dC-)induced demethylation combined with irradiation on human medulloblastoma (MB) cells, which form the most common malignant brain tumor in children.

Material And Methods: Three MB cell lines were treated with 5-aza-dC in a low-dose (0.

Design and construction of the high-speed optoelectronic memory system demonstrator.

The high-speed optoelectronic memory system project is concerned with the reduction of latency within multiprocessor computer systems (a key problem) by the use of optoelectronics and associated packaging technologies. System demonstrators have been constructed to enable the evaluation of the technologies in terms of manufacturability. The system combines fiber, free space, and planar integrated optical waveguide technologies to augment the electronic memory and the processor components.

Practical realization of massively parallel fiber-free-space optical interconnects.

We propose a novel approach to realizing massively parallel optical interconnects based on commercially available multifiber ribbons with MT-type connectors and custom-designed planar-integrated free-space components. It combines the advantages of fiber optics, that is, a long range and convenient and flexible installation, with those of (planar-integrated) free-space optics, that is, a wide range of implementable functions and a high potential for integration and parallelization. For the interface between fibers and free-space optical systems a low-cost practical solution is presented.

Planar-integrated optical vector-matrix multiplier.

We present the design of a planar-integrated optoelectronic vector-matrix multiplier. The inherent parallel-processing potential is fully exploited by optical implementation of multiplications and summations. Planar integration makes the free-space optical system compatible with electronic VLSI technologies.

Compact planar-integrated optical correlator for spatially incoherent signals.

A new, to our knowledge, approach for the planar integration of optical correlators is demonstrated. A VanderLugt-type architecture was used to allow the processing of the spatially incoherent signals of active optoelectronic smart-pixel-device arrays. In a folded optical system all passive components were implemented as a single multiple-phase-level element.

Fabrication of microprisms for planar optical interconnections by use of analog gray-scale lithography with high-energy-beam-sensitive glass.

For an integrated free-space optical interconnection system we suggest the use of microprisms to achieve large coupling angles at low loss. Prisms were fabricated in photoresist and quartz glass by analog lithography. High-energy-beam-sensitive glass was used as the gray-tone mask.

Planar-integrated talbot array illuminators.

We demonstrate the planar integration of Talbot array illuminators designed to generate one-dimensional spot arrays. The array illuminator basically consists of a phase grating and a cylindrical diffractive lens integrated as a single diffractive optical element onto a transparent glass substrate. We discuss various design aspects, and we focus on problems typical for planar-integrated free-space optics like the tilted optical axis of the system.