Reflection confocal nanoscopy using a super-oscillatory lens

A Superoscillatory lens (SOL) is known to produce a sub-diffraction hotspot which is useful for high-resolution imaging. However, high-energy rings called sidelobes coexist with the central hotspot. Additionally, SOLs have not yet been directly used to image reflective objects due to low efficiency and poor imaging properties. We propose a novel reflection confocal nanoscope which mitigates these issues by relaying the SOL intensity pattern onto the object and use conventional optics for detection. We experimentally demonstrate super-resolution by imaging double bars with 330 nm separation using a 632.8 nm excitation and a 0.95 NA objective. We also discuss the enhanced contrast properties of the SOL nanoscope against a laser confocal microscope, and the degradation of performance while imaging large objects.Comment: 17 pages, 15 figures, supplementary include

Effects of degradable Mg-Ca alloys on dendritic cell function

Degradable magnesium alloys are new materials for implants used in orthopedic and trauma surgery. The aim of this study was to investigate the influence of degradable magnesium alloys on the function of dendritic cells (DC) as these cells represent the major antigen presenting cells of the body. MgP (pure magnesium), MgCa 0.6 (0.6% calcium), MgCa 0.8 (0.8% calcium), MgCa 1.0 (1% calcium), and MgCa 1.2 (1.2% calcium) alloys were degraded in cell culture medium. In parallel, murine bone marrow-derived DC were incubated with increasing concentrations (0.1-10 mmol/L) of magnesium chloride and calcium chloride, respectively. Incubation of DC with degradation media over 6 days had no influence on cell viability and only marginal influence on DC migration. Also, the production of TNFα and expression of CD86 was not enhanced by incubation with degraded magnesium alloys. The mixed leukocyte reaction revealed that there was also no increase of the T-cell proliferation in comparison to untreated controls. However, there was a trend toward macrophage development at the expense of DC expansion and an enhanced DC migration was induced by incubation with higher magnesium concentrations. Particularly the latter should be verified in in vivo experiments. © The Author(s), 2010

A Limited Role for the Cell Cycle Regulator Cyclin A1 in Murine Leukemogenesis

The quest for novel therapeutic targets in acute myeloid leukemia (AML) is still ongoing. One of such targets, cyclin A1, was shown to be overexpressed in AML including AML stem cells. However, the function of cyclin A1 in AML is largely unknown, and the data on its impact on patients´ survival remain controversial. Therefore, we developed a transgenic mouse model of stem cell-directed inducible cyclin A1 overexpression and crossed these mice with PML-RARα-knockin mice, which develop an AML M3-like phenotype. To observe the effects of cyclin A1 loss-of-function, we also crossed PML-RARα-knockin mice to cyclin A1-knockout mice. Neither overexpression nor loss of cyclin A1 significantly altered leukemogenesis in PML-RARα-knockin mice. These findings imply that upregulation of cyclin A1 is not essential for leukemogenesis. Our data suggest that cyclin A1 does not represent a suitable target for AML therapy

Oxygen-induced p(2x3) reconstruction on Mo(112) studied by LEED and STM

The open trough-and-row Mo(112) surface serves as substrate for the epitaxial growth of MoO2. In the early stage of oxygen exposure, oxygen chemisorption induces a p(2x3) surface reconstruction of the missing row type on Mo(112). The surface structure of this reconstructed surface has been studied in detail by low-energy electron diffraction and scanning tunneling microscope. The experimental findings can be explained based on the effective medium theory for oxygen adsorption on transition-metal surfaces, providing a structure model for the oxygen-modified Mo(112) surface. The structure model allows the discussion of the oxygen-chemisorbed surface phase as a possible precursor state fo