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The Framing Camera (FC) is the German contribution to the Dawn mission. The camera will map 4 Vesta and 1 Ceres through a clear filter and 7 band-pass filters covering the wavelengths from the visible to the near-IR. The camera will allow the determination of the physical parameters of the asteroids, the reconstruction of their global shape as well as local topography and surface geomorphology, and provide information on composition via surface reflectance characteristics. The camera will also serve for orbit navigation. The resolution of the Framing Camera will be up to 12 m per pixel in low altitude mapping orbit at Vesta (62 m per pixel at Ceres), at an angular resolution of 93.7 μrad px −1 .The instrument uses a reclosable front door to protect the optical system and a filterwheel mechanism to select the band-pass for observation. The detector data is read out and processed by a data processing unit. A power converter unit supplies all required power rails for operation and thermal maintenance. For redundancy reasons, two identical cameras were provided, both located side by side on the +Z-deck of the spacecraft. Each camera has a mass of 5.5 kg.

Aiming at the derivation of a generalized procedure for the straightforward preparation of particles fluorescing in the visible and near-infrared (NIR) spectral region, different swelling procedures for the loading of the hydrophobic polarity-probe Nile Red into nano- and micrometer sized polystyrene particles were studied and compared with respect to the optical properties of the resulting particles. The effect of the amount of incorporated dye on the spectroscopic properties of the particles was investigated for differently sized beads with different surface chemistries, i.e., non-functionalized, amino-modified and PEG-grafted surfaces. Moreover, photostability and leaking studies were performed. The main criterion for the optimization of the dye loading procedures was a high and thermally and photochemically stable fluorescence output of the particles for the future application of these systems as fluorescent labels.

The unparallelede xcited-state potential-energy landscape of the chromium(III)-based dye [1] 3 + + ([Cr(ddpd) 2 ] 3 + ;d dpd = N,N'-dimethyl-N,N'-dipyridin-2-ylpyridin-2,6-diamine) enables as trong dual emission in the near infrared region. The temperature dependence of this dual emission allows the use of [1] 3 + + as an unprecedented molecular ratiometric thermometer in the 210-373 Kt emperature range in organic and in aqueous media. Incorporation of [1] 3 + + in biocompatiblen anocarriers, such as 100 nm-sized polystyrene nanoparticles and solutol micelles, providesn anodimensional thermometers operating under physiological conditions. Optical sensing of physicochemical quantities, such as temperature (T), pressure, oxygen concentration, or pH, is of tremendous importance in many fields.[1] Applications requiring T sensing range from biology( e.g.,i ntracellular thermometry) [2] and medicald iagnostics (e.g.,p oint-of-care diagnostics [3] using amplifyinge nzymatic reactions) [4] to chemical synthesis (e.g., microfluidics [5] ), and materials sciences (e.g., T-sensitive paints [6] for spatial sensing in wind tunnels). Optical T measurements utilizing T-dependentf luorometric parameters, such as luminescence intensity (or intensity ratios) and lifetime, have been achieved with different classes of molecular and nanoscale emitters. [1c, d] Examples are polymerbased nanoparticles, [7] lanthanide-based nanocrystals, [8] and DNA-based systems, such as molecular beacons (MBs). [9] Fluorometric T sensing can be done nonratiometrically,e xploiting the T sensitivity of the fluorescencei ntensity of as ingle-emissionb and (e.g.,r hodamine B), [10] which is prone to artefacts due to fluctuationsi n, for example, excitation light intensity,o rr atiometrically requiring two emission bands, one being T sensitive and one not responding to changes in T for signal referencing.R atiometric T sensing can be achieved with three design concepts:a )a combination of two emissive dyes (T-responsive probe and T-inert reference);b )acombination of two dyes whichi nteract by ad istance-dependent process, such as fluorescencer esonance energy transfer (EnT) in systems, in which dye distance is modified by T;a nd c) as ingle dye displaying dual emission (Figure 1).[1] Scenario a) is commonly achievedb ycombining two organic fluorophores in af ixed ratio, fore xample, within nanoparticles ( Figure 1a). Both dyesm ust be excitable at the same wavelength and shows pectrally distinguishable emission bands to allow separating andi ntegrating the luminescence signals for the calculation of the excitation light intensity-independent Tsensitivequotient I probe /I ref .Fluorescent T sensors, which exploit T-dependent structural features communicated as changes in fluorescencei ntensity of the reporter dyes are fluorophore-labeled MBs ( Figure 1b). [9] These flexible single-stranded oligonucleotides are either dually labeled att heir 5'-a nd 3'-ends with af luorophore and an onemissive quencher( nonratiometric M...

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Polystyrene nanoparticles (PS-NPs) were doped with an oxygen-sensitive near-infrared (NIR)-emissive palladium meso-tetraphenylporphyrin and an inert reference dye which are both excitable at 635 nm. The nanosensors were characterized with special emphasis on fundamental parameters such as absolute photoluminescence quantum yield and fluorescence lifetime. The PS-NPs were employed for ratiometric dual-wavelength and lifetime-based photoluminescent oxygen sensing. They were efficiently taken up by cultured murine alveolar macrophages, yielding a characteristic and reversible change in ratiometric response with decreasing oxygen concentration. This correlated with the cellular hypoxic status verified by analysis of hypoxia inducible factor-1α (HIF-1α) accumulation. In addition, the surface of PS-NPs was functionalized with polyethylene glycol (PEG) and the monoclonal antibody herceptin, and their binding to HER2/neu-overexpressing tumor cells was confirmed in vitro. First experiments with tumor-bearing mouse revealed a distinctive ratiometric response within the tumor upon hypoxic condition induced by animal sacrifice. These results demonstrate the potential of these referenced NIR nanosensors for in vitro and in vivo imaging that present a new generation of optical probes for oncology.

A crucial variable for methodical performance evaluation and comparison of luminescent reporters is the photoluminescence quantum yield (Φ pl). This quantity, defined as the number of emitted photons per number of absorbed photons, is the direct measure of the efficiency of the conversion of absorbed photons into emitted light for small organic dyes, fluorescent proteins, metal-ligand complexes, metal clusters, polymeric nanoparticles, and semiconductor and up-conversion nanocrystals. Φ pl determines the sensitivity for the detection of a specific analyte from the chromophore perspective, together with its molar-absorption coefficient at the excitation wavelength. In this review we discuss different optical and photothermal methods for measuring Φ pl of transparent and scattering systems for the most common classes of luminescent reporters, and critically evaluate their potential and limitations. In addition, reporter-specific effects and sources of uncertainty are addressed. The ultimate objective is to provide users of fluorescence techniques with validated tools for the determination of Φ pl, including a series of Φ pl standards for the ultraviolet, visible, and near-infrared regions, and to enable better judgment of the reliability of literature data.

[1] To date dynamical observations of the Venus clouds have delivered mainly either only short-term or long-term averaged results. With the Venus Monitoring Camera (VMC) it finally became possible to investigate the global dynamics with a relatively high resolution in space and time on a long-term basis. Our findings from manual cloud feature wind tracking in VMC UV image sequences so far show that the details of the mesospheric dynamics of Venus appear to be highly variable. Although the general rotation of the atmosphere remained relatively stable since Mariner 10, more than 30 years ago, by now, there are indications of short-term variations in the general circulation pattern of the Venus atmosphere at cloud top level. In some cases, significant variations in the zonal wind properties occur on a timescale of days. In other cases, we see rather stable conditions over one atmospheric revolution, or longer, at cloud top level. It remains an interesting question whether the irregularly observed midlatitude jets are indeed variable or simply become shielded from view by higher H 2 SO 4 haze layers for varying time intervals. Winds at latitudes higher than 60°S are still difficult to obtain track because of low contrast and scarcity of features but increasing data is being collected. Over all, it was possible to extend latitudinal coverage of the cloud top winds with VMC observations. Thermal tides seem to be present in the data, but final confirmation still depends on synthesis of Visible and Infrared Thermal Imaging Spectrometer and VMC observations on night and dayside. Although poorly resolved, meridional wind speed measurements agree mainly with previous observations and with the presence of a Hadley cell spanning between equatorial region and about 45°S latitude.