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Our research group developed a novel nano-pitted (NP) TiO2 surface on grade 2 titanium that showed good mechanical, osteogenic, and antibacterial properties; however, it showed weak hydrophilicity. Our objective was to develop a surface treatment method to enhance the hydrophilicity of the NP TiO2 surface without the destruction of the nano-topography. The effects of dilute and concentrated orthophosphoric (H3PO4) and nitric acids were investigated on wettability using contact angle measurement. Optical profilometry and atomic force microscopy were used for surface roughness measurement. The chemical composition of the TiO2 surface and the oxidation state of Ti was investigated using X-ray photoelectron spectroscopy. The ccH3PO4 treatment significantly increased the wettability of the NP TiO2 surfaces (30°) compared to the untreated control (88°). The quantity of the absorbed phosphorus significantly increased following ccH3PO4 treatment compared to the control and caused the oxidation state of titanium to decrease (Ti4+ → Ti3+). Owing to its simplicity and robustness the presented surface treatment method may be utilized in the industrial-scale manufacturing of titanium implants. [ABSTRACT FROM AUTHOR]

Reflectance images of various intact leaves were taken in four selected bands at 440, 550, 690, and 800 nm and compared with their reflectance spectra in the visible to near infra-red (range: 400 to 800 nm). The images showed high local resolution over the leaf surface (0.025 mm2 per pixel) with a low spectral resolution, whereas the reflectance spectra were acquired with a high spectral resolution (1 nm). In addition, the individual leaf samples were further characterized by their specific colorimetric values for visual impression (CIE 1931). The results demonstrate that leaf reflectance is determined by the following basic parameters: (a) the leaf pigment content (absorption of chlorophylls and carotenoids in the pigment protein complexes of chloroplasts and, in red leaves, also of epidermal anthocyanins), (b) the leaf tissue structure (size of aerial interspaces between cells, which influence leaf optical properties), and (c) the structure of the leaf surface (e.g., waxes and hairs). These in-vivo measurements of leaves have the advantage of being fast and non-destructive, with the possibility for high-throughput evaluation and repetition measurements. The data are discussed in view of their importance for basic research (e.g., stress detection) and quality assessment of plant material ranging from contact measurements to remote sensing. [ABSTRACT FROM AUTHOR]

Abstract: The wild-type barley (WT; Hordeum vulgare L.) and its chlorophyll (Chl) b-less mutant chlorina f2 (clo f2) grown under shaded conditions in a greenhouse were transferred to outdoor conditions in early June with predominantly bright sunny days. During 6 days following transfer of plants we monitored the content of photosynthetic pigments, functional state of photosystem II (PSII) by means of Chl fluorescence induction kinetics and epidermal UV-shielding efficiency using Chl fluorescence imaging technique. Clo f2 mutant was more sensitive to exposure to an enhanced natural solar irradiance than WT barley. Nevertheless, clo f2 as well as WT were able to cope with stressful outdoor conditions, as was documented by the recovery of Chl a content and the maximal photochemical efficiency of PSII (F V/F M) after an initial decline. This was due to the immediate carotenoid-mediated photoprotection, reflected by strongly increased total carotenoids content and thermal energy dissipation localized within light-harvesting complexes of PSII (assessed by non-photochemical quenching of minimal fluorescence level). The positive acclimation response was further documented by an enhanced light-saturated electron transport rate through PSII (ETR). Based on the ratios of blue- to UV-excited Chl fluorescence we found that for both WT and clo f2 epidermal UV-shielding increased clearly after transfer to outdoor conditions and reached a saturation level after 3 days. In comparison with WT, clo f2 exhibited lower ability to induce UV-shielding. The kinetics of UV-shielding development during the outdoor treatment was different for the particular leaf regions. We suggest that this is related to the different age and developmental stage of the tissue along the leaf blade. The complementarity of carotenoid-mediated photoprotection and UV-shielding in acclimation of the assimilatory apparatus to increased visible and UV radiation is discussed. [Copyright &y& Elsevier]

In the present paper, we discuss the effect of an easily implemented type of transducer electrode segmentation on the electrical and optical performance of bulk acousto-optic filters. Segmentation consisting in transducer upper electrode shaping allows realization of filters with very large interaction length with transducer electric impedances not far from the 50 Ω of the generator output’s standard impedance. Detailed experimental investigation of the influence of the electrode shape on the electrical, acoustical and acousto-optical performance has been effectuated through comparison of filters with segmented and non-segmented transducer electrodes. It was demonstrated that the positive effect of the electrode segmentation on the electrical behavior and optical wavelength dependent throughput uniformity is reduced by increased optical aperture inhomogeneity and somewhat decreased optical resolution. Practical application of both segmented and non-segmented transducers has its justification depending on the application type and available electronic environment. [Copyright &y& Elsevier]

Exposed and non-exposed halves of field-grown berries of the white grapevine Vitis vinifera L. cv. Pinot Blanc at various stages of ripeness were analysed using chlorophyll fluorescence imaging. The stage of ripeness was classified by the total sugar concentration which ranged between 120 and 300 g L -1 for the different berries but was similar in the exposed and the non-exposed half of individual berries. Fluorescence was excited in the UV-A and the blue spectral region and detected at red as well as far-red wavelengths. At both emission ranges, UV-excited fluorescence was weak and required correction for the contribution of small false signals. After correction, in vivo UV screening by berry skins was derived from the ratio of UV-A to blue-excited fluorescence intensities, and a relationship between in vivo UV screening and flavonol quantity was established: the quantity of flavonols was determined by spectral analysis of extracted phenolics. Significantly high flavonol concentrations, and effective in vivo UV screening, were detected in most exposed half-berries at sugar concentrations higher than 200 g L -1 but not in non-exposed samples. This suggests that radiation-exposure conditions determine flavonol synthesis. Based on the absence of flavonol accumulation in exposed half-berries with sugar concentrations smaller than 200 g L -1 , however, it is suggested that berries need to arrive at an advanced stage of ripeness before responding to radiation-exposure by synthesising large amounts of UV-protecting flavonols. Chlorophyll degradation, which was followed by blue-excited intensities of far-red fluorescence, progressed in parallel with increasing sugar content suggesting that chlorophyll degradation is associated with berry ripening. In addition, exposure to sunlight appeared to slightly stimulate chlorophyll decay.