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The use of aluminium(III) and aluminium(I) species in synthetic organic and organometallic chemistry has been reviewed. Aluminium(III) catalysts have been identified as effective π- and σ-Lewis acids. In addition, a substituent and/or (chiral) ligand at the Al(III) center have been demonstrated to enable cooperative (asymmetric) catalysis, following reaction patterns such as insertion/migration, σ-bond metathesis, and formal C–H bond or C–C bond activation. Aluminium(I) compounds have been shown to display their significant potential as a Lewis base, an ambiphilic reagent, or a reductant. Finally (reversible) oxidative addition and reductive elimination processes in the context of C–H bond and C–C bond cleavage have been summarised.

The catalytic and significant stoichiometric use of sodium species as a single metal mediator in molecular organic synthesis has been reviewed. Specific sodium compounds have been identified as: a Lewis acid catalyst; a critical component of a Brønsted acid catalyst; a critical component of a Lewis base or Brønsted base catalyst; electron-rich sodium species may also potentially trigger the formation of radical intermediates. In certain cases, (chiral) sodium compounds have been shown to be a pre-catalyst in (asymmetric) phase-transfer catalysis. Finally, sodium species have proved to display increased reactivity and/or selectivity in the catalysis facilitated by another metal compound (via modification of the catalyst structure and/or anion metathesis).

Purpose To evaluate retreatment indications/morphologic responses to ranibizumab monotherapy and combination with verteporfin photodynamic therapy (PDT). Methods A total of 40 patients received 3 monthly intravitreal ranibizumab 0.3 mg injections combined with either PDT or sham PDT at baseline (1:1) followed by as-needed ranibizumab based on predetermined vision/anatomical criteria. Results Retreatment criteria were visual acuity (VA) loss (59%/58%), central retinal thickness (CRT) increase (27%/26%), or both (14%/16%). One month before retreatment, intraretinal cysts (IRC) were present in 84%/74%, subretinal fluid (SRF) in 70%/63%, and at least one of them in 84%/89% of eyes. A significant decrease in mean leakage area, IRC, and SRF as well as a reduction in presence of hemorrhages and hard exudates occurred in both treatment groups at 12 months (compared to baseline). Conclusions Retreatment indications were mostly based on VA loss, probably due to the quantitative optical coherence tomography criterion. Intraretinal cysts and SRF were earlier predictors for recurring choroidal neovascularization (CNV) activity than CRT/VA changes. Both treatment strategies were equally potent in reducing CNV activity.

Fluxes of mineral nutrients in the xylem are strongly influenced by interactions with the surrounding stem tissues and are probably regulated by them. Toward a mechanistic understanding of these interactions, we applied stable isotope tracers of magnesium, potassium, and calcium continuously to the transpiration stream of cut bean (Phaseolus vulgaris) shoots to study their radial exchange at the cell and tissue level with stem tissues between pith and phloem. For isotope localization, we combined sample preparation with secondary ion mass spectrometry in a completely cryogenic workflow. After 20 min of application, tracers were readily detectable to various degrees in all tissues. The xylem parenchyma near the vessels exchanged freely with the vessels, its nutrient elements reaching a steady state of strong exchange with elements in the vessels within 20 min, mainly via apoplastic pathways. A slow exchange between vessels and cambium and phloem suggested that they are separated from the xylem, parenchyma, and pith, possibly by an apoplastic barrier to diffusion for nutrients (as for carbohydrates). There was little difference in these distributions when tracers were applied directly to intact xylem via a microcapillary, suggesting that xylem tension had little effect on radial exchange of these nutrients and that their movement was mainly diffusive.

A new approach to trace the transport routes of macronutrients in plants at the level of cells and tissues and to measure their elemental distributions was developed for investigating the dynamics and structure-function relationships of transport processes. Stem samples from Phaseolus vulgaris were used as a test system. Shock freezing and cryo-preparation were combined in a cryogenic chain with cryo-time-of-flight secondary ion mass spectrometry (cryo-ToF-SIMS) for element and isotope-specific imaging. Cryo-scanning electron microscopy (cryo-SEM) was integrated into the cryogenic workflow to assess the quality of structural preservation. We evaluated the capability of these techniques to monitor transport pathways and processes in xylem and associated tissues using supplementary sodium (Na) and tracers for potassium (K), rubidium (Rb), and 41K added to the transpiration stream. Cryo-ToF-SIMS imaging produced detailed mappings of water, K, calcium, magnesium, the K tracers, and Na without quantification. Lateral resolutions ranged from 10 μm in survey mappings and at high mass resolution to approximately 1 μm in high lateral resolution imaging in reduced areas and at lower mass resolution. The tracers Rb and 41K, as well as Na, were imaged with high sensitivity in xylem vessels and surrounding tissues. The isotope signature of the stable isotope tracer was utilized for relative quantification of the 41K tracer as a fraction of total K at the single pixel level. Cryo-SEM confirmed that tissue structures had been preserved with subcellular detail throughout all procedures. Overlays of cryo-ToF-SIMS images onto the corresponding SEM images allowed detailed correlation of nutrient images with subcellular structures.

Diabetes Mellitus (DM) is a serious medical problem that causes long-term systemic complications and considerable associated morbidity. DM can cause retinopathy (DRP), maculopathy, cataract, optic neuropathy, defects of eye muscles. DM is a risk factor for acute infectious conjunctivitis, bacterial keratitis, herpes virus infections and endophtalmitis. Elevated blood glucose induces structural, physiological and hormonal changes which affect retinal capillaries. DRP is recognized by loss of pericyte function and capillary occlusions together leading to breakdown of blood-retinal barrier, edematous changes and proliferation of vessels and fibrous tissue. Depending on stage of DRP, there are different preferable therapeutic approaches applied. In the case of ETDRS, in the area of leakage focal treatment should be performed, while panretinal photocoagulation is applied towards ischemic areas or beginning proliferations. Vitreal haemorrhage followed by fibroproliferative changes or tractional retinal detachment is treated by vitrectomy alone or in combination with ILM peeling. In pathogenesis of DRP, Insulin Growth Factor (IGF-1) can play an important role in production of VEGF (Vascular Endothelial Growth Factor). Hypoxia can up-regulate VEGF expression levels leading to pathologic ocular neovascularisation. An application of intravitreal corticosteroid treatment modulates vascular permeability by suppressing the production of VEGF, reducing both extracellular matrix metalloproteinase activity and basic fibroblast growth factor, decreasing major histocompatibility complex 2 Ag expression levels, and inhibiting activity of inflammatory cells. Clinical effects of treatment using intravitreal corticosteroids are evaluated by reduction of macular thickness and visual improvement. Intravitreal use of Anti-VEGF drugs, Pegaptanib, Ranibizumab and Bevacizumab can modify vasoproliferation, trigger macular edema, and, therefore, influence a prognosis for visual loss.

In a controlled prospective randomized study we evaluated the effectiveness of intraarticular injected hyaluronic acid regarding the changes in the parameters dynamometry, synovial oxygen partial pressure, intraarticular temperature and the knee joint function (Lequesne score). We examined 18 patients with osteoarthritis in both knee joints (Kellgren classification II or III according to x-ray) in right/left comparison. The evaluated parameters were measured before and after a 5-week treatment phase with 5 intraarticular injections (one injection per week). With regard to the efficacy results changes in dynamometric measurement for flexion and extension (for all angular velocities) and Lequesne-score indicate a marked improvement after treatment with hyaluronic acid. The differences between treated and untreated knee were significant. In extension the p-value was 0.0008 and in flexion p = 0.0015. The p-value of the Lequesne-index between the verum and control group was p = 0.0002. After treatment values for oxygen pressure were higher than at baseline and for the intraarticular temperature a small decrease at the end of the treatment phase was documented. The intraarticular injection of hyaluronic acid is effective and safe in the treatment of patients with gonarthrosis. The treatment resulted in a functional improvement of the knee joint and had a good pain-lowering effect in patients suffering from gonarthrosis.

Oxygen partial pressure is directly related to the vascularisation of different tissues. Different investigations in tissue (muscle, kidney, brain, heart, bone etc.) proved this correlation. The development of a special flexible microcatheter named Licox enables us to do measurements of intraarticular oxygen partial pressure under physiological and pathological conditions for the first time. The aim of this study was to examine the influence of different knee joint stresses on the intraarticular oxygen partial pressure under normal conditions and in osteoarthritis. The results showed that the different exercise patterns influence the intraarticular oxygen partial pressure. Patients with osteoarthritis showed a lower increase of the intraarticular oxygen partial pressure compared to the control group. This phenomenon is directly correlated to degree velocity of the isokinetic exercises. The same findings occur under ergometric conditions. The method permits functional, intraarticular in vivo measurements under different exercise patterns. For the very first time we were able to measure the influence of the joint movement on the intraarticular process of nutrition under physiological and pathological conditions. Different therapy concepts in osteoarthritis can be evaluated directly in vivo for the first time.

AIM: The aim of this study was to assess the influence of culture conditions on the differentiation of human chondrocytes expanded in monolayer (2 D) or a three-dimensional (3 D) biodegradable collagen type I matrix, with regard to chondrocyte-specific markers. METHOD: Human arthrotic chondrocytes were taken from nine adult donors (average age 72.1 years) undergoing knee replacement. The isolated cell suspensions were split and cultivated either in a 3-dimensional collagen gel (3 D) or in a monolayer (2 D). The amounts of mRNA for collagen I and II, aggrecan and melanoma inhibitory activity (MIA) were quantified by means of real-time PCR at different times. RESULTS: The 2 D-passaged cells showed a significant increase of collagen I between P 00 and P 01 (p = 0.009), whereas the expression of collagen II decreased significantly (p = 0.022). There was no significant change for collagen I in 3 D-cultivation, whereas the collagen II expression decreased significantly after 2 to 4 weeks (p = 0.001). CONCLUSION: Human adult chondrocytes obtained from elderly patients showed a decreased expression of collagen II with increased passaging in the monolayer (2 D). The decrease was delayed in 3 D-cultivation. We thus question the assumption that the dedifferentiation of chondrocytes can be prevented or reversed by 3 D-cultivation. Based on our results, we recommend the use of freshly isolated and therefore sparsely dedifferentiated chondrocytes for transplantation.

Our aim was to investigate the relationship between urinary excretion of deoxypyridinoline (DPD) as a marker of bone resorption, and Perthes’ disease. There were 39 children with Perthes’ disease in the florid stage who collected first-morning urine samples at regular intervals of at least three months. The level of urinary DPD was analysed by chemiluminescence immunoassay and was correlated with the radiological stage of the disease as classified by Waldenström, and the severity of epiphyseal involvement according to the classification systems of Catterall and Herring. The urinary DPD levels of a group of 44 healthy children were used as a control.The median urinary DPD/creatinine (CREA) ratio was significantly reduced (p < 0.0001) in the condensation stage and increased to slightly elevated values at the final stage (p = 0.05) when compared with that of the control group. Herring-C patients showed significantly lower median DPD/CREA ratios than Herring-B patients (p = 0.03). The significantly decreased median DPD/CREA ratio in early Perthes’ disease indicated a reduced bone turnover and supports the theory of a systemic aetiology. Urinary levels of DPD may therefore be used to monitor the course of Perthes’ disease.

AIM Scaffolds for the cultivation of chondrocytes are of increasing importance. So far, only little is known about their biomechanical properties. The present preliminary study addresses the biomechanical characteristics of a new collagen type I scaffold for the cultivation of chondrocytes. MATERIAL AND METHODS Human chondrocytes were amplified in a monolayer and then cultivated in a 3D-scaffold over a period of up to 6 weeks. The biomechanical tests addressed the properties under uniaxial compression including stiffness and viscoelastic characteristics (creep and retardation). The obtained values were normalized against the thickness of the specimens and expressed as ratios. In addition, we present histological and quantitative PCR results (for collagen type II and aggrecan). RESULTS The maximum force (or penetration force) revealed its highest values after a period of seven days. At this time the median value was 40 mN/mm. In the following period, a marked drop of the values was observed (19.8 mN/mm). With respect to the creep properties, we did not find any major changes over the period of six weeks. The median values were between 0.24 and 0.29 mm/mm. There were no significant differences between the samples seeded with chondrocytes and those which served as controls. A re-expansion of the samples was found with median values between 0.026 and 0.049 mm/mm (retardation). However, the original thickness was not reached after a period of 30 seconds with relief of the strain. Again, major differences of the values with respect to the duration of cultivation were not observed. Light microscopy revealed collagen type II and proteoglycans only in the pericellular region. CONCLUSION In this study not all of the biomechanical properties of the cultivated tissue were investigated. The limitation of the tests to stiffness and viscoelastic properties was reasonable in view of a potential routine use. In addition, it may facilitate a comparison between different matrix systems. In our study, the cultivation of cells within the collagen matrix did not alter the mechanical properties of the scaffold.

before and after Hyaluronic Acid Therapy. Aim: In the study we evaluted the effectiveness of intraarticular injected hyaluronic acid (Hyalart®) with regard to the changes in the parameters maximal isokinetic muscle strength, total work, pain at rest, and pain under toad. Method: We examined 43 patients with osteoarthritis in both knee joints (Kellgren II or II according to X-ray) in right/left comparison. We used the isokinetic system Cybex 600 for measuring the maximal isokinetic muscle strength and the total work. We used the visual analog scale for the pain.The evaluated parameters were measured before and after a 5-week treatment phase with 5 intraarticular injections (one injection per week with 20 mg hyaluronic acid). Results: In knees treated with hyaluronic acid the mean peak torque of the knee extensor was 57 ± 26.15/32 ± 19.63 Nm vs. 77.17 ± 32.54/47.83 ± 21.43 Nm after (p 0.01) between treated and untreated knee were found for total work of the extensor and flexor of the knee. The pain at rest decreased from 3.83 ± 1.72 cm to 1.36 ± 1.42 cm and the pain under load decreased from 7.57 ± 1.34 cm to 3.75 ± 1,32 cm in the treated knee group (p < 0,01). Conclusion: The intraarticular injection of hyaluronic acid is effective and safe in the treatment of patients with gonarthrosis. The treatment resulted in a functional improvement of the knee joint and had a good pain lowering effect in patients suffering from gonarthrosis.

Previous dielectric relaxation measurements of glycerol and propylene carbonate and new results on propylene glycol performed below the conventional glass transition temperatures T_(g) after long periods of aging all show that the excess wing (a second power law at higher frequencies) in the isothermal dielectric loss spectrum, develops into a shoulder. These results suggest that the excess wing, a characteristic feature of a variety of glass-formers, is the high frequency flank of a Johari–Goldstein β-relaxation loss peak submerged under the α-relaxation loss peak. With this interpretation of the excess wing assured, the dielectric spectra of all three glass-formers measured at temperatures above T_(g) are analyzed as a sum of a α-relaxation modeled by the Fourier transform of a Kohlrausch–Williams–Watts function and a β-relaxation modeled by a Cole–Cole function. Good fits to the experimental data have been achieved. In addition to the newly resolved β-relaxation on propylene glycol, the important results of this work are the properties of the β-relaxation in this class of glass-formers in the equilibrium liquid state obtained over broad frequency and temperature ranges.

A detailed dielectric investigation of liquid, supercooled liquid, and glassy ethanol reveals a third relaxation process, in addition to the two processes already known. The relaxation time of the newly detected process exhibits strong deviations from thermally activated behavior. Most important, this process is the cause of the apparent excess wing, which was claimed to be present in the dielectric loss spectra of glass-forming ethanol. In addition, marked deviations of the spectra of ethanol from the scaling proposed by Dixon and Nagel have been detected., 8 pages including 4 figures submitted to Phys. Rev. B

The effects of a slow-release N-enriched rock powder on soil chemistry, on the development of the soil vegetation (field layer vegetation), on the nutritional status of pine seedlings (Pinus sylvestris L.), and on decomposition rates of cellulose in lignite-poor mine spoils were studied. In the initial phase after afforestation fertilization caused a significant increase in NO3−-N concentrations in the soil solution of the top-soil (0–60 cm). Subsequently, NO3−-N concentrations of all N fertilized treatments decreased with the exception of the highest N application area (500 kg N ha−1). This decrease of NO3−-N concentrations was related to the establishment of a field layer vegetation, which developed according to the amount of N applied. In the above-ground phytomass of the field layer vegetation a maximum N accumulation amount of 22 kg ha−1 was measured. Cellulose decomposition increased with higher N application rates. In the second year after N-fertilization, the pine needles indicated insufficient supply for almost all nutrients except for N. The deficiency symptoms were most pronounced at the plots that had received the highest amounts of nitrogen. This phenomenon appears to be related to the competition by the field layer vegetation.

Previously, we gravimetrically examined the Drosophila embryos' rate of air drying after each step in their permeabilization; namely, (1) dechorionation, (2) isopropanol exposure, and (3) heptane/butanol exposure. Here we describe a physical model characterizing the dehydration and compare the theory with the experimental kinetics. The model is based on those of Eyring. It treats the net flux (Jnet) through the membrane as the sum of two opposing fluxes (air → embryo {a{ and embryo → air {i{. Each flux is the product of a kinetic constant (k), the number of embryos in the sample (n), and the water concentration (C). Thus, Jnet = kanCa −kinCi. The relationship between ki and ka, for embryos in steady state with room humidity, is kika = CaCi. Determining the k values requires the mass and density of the embryo solids, n, Ci, as a function of drying time, and the steady-state value of Ci. Following integration of the flux equation, linear regression was used to determine ki. ka was computed using the previous equation. The resulting values for ka are 3.96, 26.70, 17.40, and 258.00 mn3/embryo·h for untreated embryos and embryos treated with, (1), (l) + (2), (l) + (2) + (3), respectively. The corresponding values for ki (×106) are 484, 3680, 2800, and 47,300 mm3/embryo·h.

The inhalation of (222) Rn (radon) decay products is one of the most important reasons for lung cancer after smoking. Stony building materials are an important source of indoor radon. This article describes the determination of the exhalation rate of stony construction materials by the use of commercially available measuring devices in combination with VOC emission test chambers. Five materials - two types of clay brick, clinker brick, light-weight concrete brick, and honeycomb brick - generally used for wall constructions were used for the experiments. Their contribution to real room concentrations was estimated by applying room model parameters given in ISO 16000-9, RP 112, and AgBB. This knowledge can be relevant, if for instance indoor radon concentration is limited by law. The test set-up used here is well suited for application in test laboratories dealing with VOC emission testing.

Background: Xenograft mouse models represent helpful tools for preclinical studies on human tumors. For modeling the complexity of the human disease, primary tumor cells are by far superior to established cell lines. As qualified exemplary model, patients’ acute lymphoblastic leukemia cells reliably engraft in mice inducing orthotopic disseminated leukemia closely resembling the disease in men. Unfortunately, disease monitoring of acute lymphoblastic leukemia in mice is hampered by lack of a suitable readout parameter. Design and Methods: Patients’ acute lymphoblastic leukemia cells were lentivirally transduced to express the membranebound form of Gaussia luciferase. In vivo imaging was established in individual patients’ leukemias and extensively validated. Results: Bioluminescence in vivo imaging enabled reliable and continuous follow-up of individual mice. Light emission strictly correlated to post mortem quantification of leukemic burden and revealed a logarithmic, time and cell number dependent growth pattern. Imaging conveniently quantified frequencies of leukemia initiating cells in limiting dilution transplantation assays. Upon detecting a single leukemia cell within more than 10,000 bone marrow cells, imaging enabled monitoring minimal residual disease, time to tumor re-growth and relapse. Imaging quantified therapy effects precisely and with low variances, discriminating treatment failure from partial and complete responses. Conclusions: For the first time, we characterized in detail how in vivo imaging reforms preclinical studies on patient-derived tumors upon increasing monitoring resolution. In the future, in vivo imaging will enable performing precise preclinical studies on a broad range of highly demanding clinical challenges, such as treatment failure, resistance in leukemia initiating cells, minimal residual disease and relapse.

In the laser assisted electron beam evaporation (LEBE) a fused silica substrate is heated by cw CO2 laser irradiation before and during film condensation. HfO2 and Y2O3 films are prepared with this technique. The optical and structural properties of the coatings are investigated by spectral-photometric transmission measurement (refractive index), laterally resolved ellipsometry (lateral index and thickness profile calculations), and X-ray diffraction (structure). The surface morphology is characterized by lateral force microscopy, a special mode of atomic force microscopy. Laser damage threshold values are also studied at 248 nm. It is observed that the LEBE deposited films have a rough columnar, crystalline structure and increased refractive index and laser damage threshold values in comparison to amorphous films prepared by conventional EBE.

The interaction of H 2 with the ordered Cu 3 Pt(111) surface has been studied with Auger electron spectroscopy (AES), low energy electron diffraction (LEED), thermal desorption spectroscopy (TDS), UV-photoelectron spectroscopy (UPS), and work function measurements (ΔO). The ordered Cu 3 Pt(111) surface consists of a 2×2 lattice of isolated Pt atoms completely surrounded by Cu atoms (d Pt-Pt =5.2 A). In contrast to Cu(111) hydrogen adsorption does take place. TD spectra exhibit only one H 2 desorption state of second order desorption kinetics and show no evidence for a compression of the H layer at higher coverages in contrast to Pt(111). The H induced changes in the substrate valence band spectra (UPS) suggest H adsorption at Pt sites

A proposed new integrated optical microphone, in which micromachining and integrated optics in silicon are combined, is described. It is an interferometric sensor with a hollow parallel-plate waveguide as the phase modulator. One of the walls of this hollow waveguide is the gold-coated silicon nitride diaphragm. If the membrane is displaced by sound pressure, the phase of a light wave propagating in the waveguide is modulated. All-silicon waveguides are used for good coupling of light between glass fibers and the modulator. The fabrication process will be very short and compatible to standard semiconductor technology. An equivalent noise level of 45 dB assuming a bandwidth of 10 kHz can be estimated for the microphone, which has not yet been realized. The sensor has dimensions of 10 mm×3 mm×0.56 mm with a 1 mm×1 mm membrane area.

The coadsorption of hydrogen and CO on the ordered Cu3Pt(111) surface has been studied using low energy electron diffraction (LEED), thermal desorption spectroscopy (TDS), UV-photoelectron spectroscopy (UPS), and high resolution electron energy loss spectroscopy (HREELS). The main feature of the ordered Cu3Pt(111) surface is a 2 × 2 structure of the Pt atoms in the surface, hence, Pt atoms are completely surrounded by Cu atoms. At temperatures above 180 K CO adsorbs on top of the Pt atoms. A constant hydrogen desorption temperature regardless of the CO pre-coverage in TDS indicates a repulsive CO-H interaction. In this case the HREEL spectra of the CO are not different from the spectra of CO on the clean surface. Dosing CO on a hydrogen saturated surface at 130 K leads to a shift of the hydrogen TD spectra to lower temperatures. Eventually this shift will stop accompanied by the occurrence of a new higher coordination CO adsorption state (HREELS) that has not been found on the clean surface. The experiments suggest a short-range repulsive interaction between hydrogen and CO on the ordered Cu3Pt(111) surface.

The interaction of Xe, CO and H 2 with the ordered Cu 3 Pt(111) surface has been studied by thermal desorption spectroscopy (TDS), Auger electron spectroscopy (AES), low-energy electron diffraction (LEED), UV-photoelectron spectroscopy (UPS) and work-function measurements ( ΔΦ ) in the temperature range 50–400 K. In contrast to the Xe results CO and H 2 adsorption shows a site selectivity suggesting a local character of the interaction. After adsorption at 50 K in the case of CO two different chemisorption states are observed, CO on Pt atoms and CO on Cu sites, whereas in the case of H 2 , dissociative adsorption via Pt atoms is found with only one Pt-like adsorption state. In spite of this site selectivity the properties of CO and H adsorption on the Pt-like sites are completely different from those found on pure Pt(111), namely the desorption energy is significantly lower. In the case of CO this difference can only be explained in terms of a change of the electronic properties of Pt by alloying with Cu (ligand effect), whereas in the case of H adsorption additionally an ensemble effect (different adsorption sites) has to be included.

In this paper the effects of type of cement, of water/cement-ratio and of surface coatings on the stress corrosion of cement mortars in 5%- ammonium sulfate solution are reported. The effects observed for different cements and water/cement-ratios in stress corrosion correspond to the effects observed in classical corrosion, i.e if mechanical stresses are not present. Coated specimens however show a distinct decline in strength when a mechanical stress acts simultaneously to a chemical stress and when the coatings are destroyed by cracks, respectively. Thus, the use of coatings has to be reconsidered, taking into account stress corrosion.

Lateral exchange of water and nutrients between xylem and surrounding tissues helps to de-couple uptake from utilization in all parts of a plant. We studied the dynamics of these exchanges, using stable isotope tracers for water (H 2 18 O), magnesium ( 26 Mg), potassium ( 41 K) and calcium ( 44 Ca) delivered via a cut stem for various periods to the transpiration stream of bean shoots (Phaseolus vulgaris cv. Fardenlosa Shiny). Tracers were subsequently mapped in stem cross-sections with cryo-secondary ion mass spectrometry. The water tracer equilibrated within minutes across the entire cross-section. In contrast, the nutrient tracers showed a very heterogeneous exchange between xylem vessels and the different stem tissues, even after 4 h. Dynamics of nutrients in the tissues revealed a fast and extensive exchange of nutrients in the xylem parenchyma, with, for example, calcium being completely replaced by tracer in less than 5 min. Dilution of potassium tracer during its 30 s transit in xylem sap through the stem showed that potassium concentration was up-regulated over many hours, to the extent that some of it was probably supplied by phloem recirculation from the shoot.

The Fraunhofer IPT investigates the basic interactions in chemical-mechanical polishing of glass. The knowledge is put together in a monitoring system and the fundamental understanding is applied to current issues in full- and sub-aperture polishing.

In the modular advanced stellarator W7-AS, the plasma performance and the main characteristics of the plasma-wall interaction are strongly affected by the three-dimensional edge topology. Both limiter-and separatrix-dominated configurations are possible. TiC and bulk-boronized limiter materials have been used. The impurity behaviour and the accessible plasma parameter ranges are compared for different limiter and wall conditions. With limiters, optimum plasma performance in currentless ECRF-or NBI-heated discharges was achieved with bulk-boronized graphite limiter material and boronized walls. Solid target sputter boronization, however, was found to be ineffective in comparison with boronization by He/B 2 H 6 glow discharges. For separatrix-dominated discharges, conditioning by wall coating has short-term effects only. Enhanced, localized plasma outflow to the wall due to islands at the boundary quickly erodes the layers. The possibility to develop a divertor concept is discussed. Basic properties of the plasma edge edge as derived from Langmuir probes and limiter calorimetry are described. Modeling is complicated by three-dimensionality. In a first approach, a 1D edge transport model on the basis of distinct flux bundles is applied.

Density limit investigations on ASDEX have been performed under a variety of conditions: ohmically heated and neutral injection heated plasmas in H2, D2 and He have been studied in different divertor configurations, after various wall coating procedures, with gas puff and pellet fuelling, and in different confinement regimes with their characteristically different density profiles. A detailed description of the parametric dependence of the density limit, which in all cases is a disruptive limit, is given. This limit is shown to be a limit to the density at the plasma edge. Therefore, the highest densities corresponding to neRqa/Bt>30*1019 m-2.T-1 are obtained with centrally peaked ne profiles. Radiation from the main plasma at the density limit is always significantly below the total input power. The plasma disruption is due to an m=2 instability which for medium and high qa is preceded by one or more minor disruptions. In this range of qa, the disruptive instability is initiated by the occurrence of a Marfe on the high field side as a consequence of strong plasma cooling in this region. The duration of the Marfe increases with increasing distance between the plasma edge and the q=2 surface. After penetrating onto closed flux surfaces the Marfe leads to a current contraction and a subsequent destabilization of the m = 2 mode. In helium plasmas a strongly radiating, poloidally symmetric shell is observed before the density limit instead of a Marfe. An instantaneous destabilization of this mode is observed at low qa. Detailed measurements of plasma edge and divertor parameters close to the density limit indicate the development of a cold, dense divertor plasma before the disruption. Models describing the scrape-off layer and the divertor region predict an upper limit to the edge density at low divertor temperatures according to power balance considerations. Their relations to the experimental findings, especially the low field side cooling, ar

Cu3Pt undergoes a bulk order-disorder phase transition at around 850 K. The interaction of CO with the ordered as well as a “disordered” (with a somewhat higher Pt concentration) surface of the Cu3Pt(111) alloy in the temperature range 50–400 K was studied with AES, LEED, TDS, UPS and work function (WF) measurements. On both Cu3Pt(111) surfaces a chemisorbed CO state is observed. The two photoemission peaks characteristic for chemisorbed CO are found at 9.2 eV (5σ/1π) and 11.7 eV (4σ), similar as for CO/Pt(111). In contrast to the CO/Cu systems no satellite was observed. Above 1 ML at 50 K, on both surfaces three new states in the UPS spectra are present at 7.6 eV (5σ), 10.8 eV (1π) and 13.2 eV (4σ) for the ordered surface and at 7.2 eV (5σ), 10.7 eV (1π) and 13.0 eV (4σ) for the “disordered” surface indicating a physisorbed CO state. The chemisorbed CO desorbs at 330 K from ordered and at 300 K from “disordered” Cu3Pt(111) which raises the WF by no more than 0.05 eV. The stronger interaction of CO with the ordered Cu3Pt(111) surface than with the “disordered” surface, suggests a possible ligand effect from Cu on Pt.

The interaction of Xe with the ordered and a disordered Cu3Pt(111) surface in the temperature range 50–120 K was investigated with AES, LEED, TDS, UPS and work function (WF) measurements. In the Xe coverage range of 0.1–0.6 ML on both surfaces the shape and the binding energy (BE) of the Xe5p12 and 5p32 UPS peaks are practically independent of the Xe coverage. The splitting of the 5p32 peak in the UPS spectra indicates that Xe condensation takes place at low coverages. This is confirmed by LEED; already at θ ≈ 0.2 ML a √3 × √3 R30° Xe superstructure is observed on both surfaces. In particular, only one 5p12 signal is observed on either surface and its BE is related to the respective macroscopic WF. At higher coverages both 5p signals broaden slightly to the higher BE side. This suggests that a two-dimensional (2D) phase transition (2D Xecommensurate-2D Xeincommensurate) occurs on both surfaces independent of their different surface composition. The results support the notion that the Xe-substrate interaction potential on both alloy surfaces is rather homogeneous in character.

The interaction of potassium with Rh(111) was studied by AES, REELS, LEED, TDS, UPS and work function (WF) measurements. At low coverages (ΘK < 0.1) Φ decreases linearly followed by a shallow minimum at ΘK ≈ 0.2 and a slight reincrease. Three different LEED K-superstructures at ΘK = 0.25 (2 × 2), ΘK = 0.33 (√3 × √3 R30°) and at ΘK = 0.5 (2 × 2) have been observed corresponding to a nearest K–K neighbour distance for the first two structures of 5.38A and 4.66A, respectively, The √3 × √3 R30° structure is compressed by 6% compared to the surface density of (110) K planes. The multilayer desorption in TDS is observed only at K-coverages beyond 0.5 which is generally correlated with a metallic (potassium like) character of the overlayer. In the K-coverage range 0–0.33 the electronic binding energy of the K(3p) level shifts to lower binding energy (18.4–17.8 eV). Above ΘK = 0.5 a new K(3p) peak develops at the sane energetic position as it is observed for a thick potassium film (18.6 eV). The transition of the electronic properties of the K-overlayer character is also ionic (low coverage) to a covalent (high coverage) bonding character is also reflacted in the electron loss experiment. Only above ΘK = 0.5 the plasmon loss characteristic of thick metallic K at 2.5 eV can be detected, even though already around 0.33 the K–K nearest neighbour distance corresponds to the covalent value.

Intravascular application of goat anti-rabbit immunoglobulin E (IgE) was used to stimulate parenchymal mast cells in situ in perfused rabbit lungs. Sustained pulmonary arterial pressure rise was evoked in the absence of lung vascular permeability increase and lung edema formation. Early prostaglandin (PG) D2 and histamine release into the perfusate was documented, accompanied by more sustained liberation of cysteinyl leukotrienes (LT), LTB4, and PGI2. The quantities of these inflammatory mediators displayed the following order: histamine greater than cysteinyl-LT greater than PGI2 greater than LTB4 greater than PGD2. Pressor response and inflammatory mediator release revealed corresponding bell-shaped dose dependencies. Cyclooxygenase inhibition (acetylsalicylic acid) suppressed prostanoid generation, increased LT release, and did not substantially affect pressor response and histamine liberation. BW755 C, a cyclo- and lipoxygenase inhibitor, blocked the release of cysteinyl-LT and markedly reduced the liberation of the other inflammatory mediators as well as the pressor response. The H1-antagonist clemastine caused a moderate reduction of the anti-IgE-provoked pressure rise. We conclude that intravascular anti-IgE challenge in intact lungs provokes the release of an inflammatory mediator profile compatible with in situ lung parenchymal mast cell activation. Pulmonary hypertension represents the predominant vascular response, presumably mediated by cysteinyl-LT and, to a minor extent, histamine liberation.

The Xe adsorption on NiAl(110) and Al(110) has been studied at 45 K by ultraviolet photoelectron spectroscopy (UPS), thermal desorption spectroscopy (TDS) and low‐energy electron diffraction (LEED). On both surfaces a two‐dimensional (2D) Xe Gas‐2D Xe solid phase transition is observed. On NiAl(110) this 2D‐phase transition occurs at Θ(Xe)≊0.3 monolayer (ML) as judged by UPS and TDS. A Xe induced LEED pattern suggesting long range order, however, is only observed beyond Θ(Xe)≊0.5 ML. On Al(110) the 2D Xe condensation occurs already at a coverage of Θ(Xe)≊0.1 ML, most likely within the troughs, because the Xe induced LEED pattern exhibits the same periodicity (perpendicular to the surface troughs) as the Al(110) substrate.

The disposal of coal combustion residues (CCR) has led to a significant consumption of land in the West Balkan region. In Tuzla (Bosnia and Herzegovina) we studied previously soil-covered (farmed) and barren CCR landfills including management practises, field ageing of CCR and the transfer of trace elements into crops, wild plants and wastewaters. Soil tillage resulted in mixing of cover soil with CCR. Medicago sativa showed very low Cu:Mo ratios (1.25) which may cause hypocuprosis in ruminants. Total loads of inorganic pollutants in the CCR transport water, but not pH (12), were below regulatory limits of most EU countries. Arsenic concentrations in CCR transport water were

Edge conditions have been varied on ASDEX by altering the divertor configuration and wall conditioning. Introduction of bypasses which allow neutral gas to enter the main chamber from the divertor by paths other than through the divertor neck greatly increased the power threshold for the H-mode and led to poorer H-mode quality. At the same time a regime of improved ohmic confinement (IOC) made its appearance. Closing the bypasses and boronization of the walls restored good H-mode behavior in a wide parameter range. The degree of improved ohmic confinement was found to be a function of recycling and plasma purity. The IOC effect with all its facets could be provoked in clean discharges by neon puffing. An explanation is provided in a simple theory which links impurity radiation and power flow Psol into the scrape-off layer (SOL) to the edge density. In like manner, observed isotopic effects of density at the separatrix can be related to an isotopic dependence of Psol. A subset of ASDEX density-limit discharges may also be understood in terms of edge parameters and Psol, thereby sheading light on the weak power scaling observed for the density limit with auxiliary heating.

Alkali silicates react with isocyanates to form hard and brittle materials. The mechanical properties of these organo-mineral cements depend on the types of sodium silicate and isocyanates that are combined, and on the accelerating and modifying agents that may be added. The flexural strength of the pure hardened cements can reach 10 M Pa, and the compressive strength 30 M Pa. The setting times vary from a few seconds to several weeks. The hardened cement seems to be an intimate mixture of at least two phases: an organic phase consisting of a polyisocyanate resin, and an inorganic phase consisting mainly of an amorphous silica gel and various carbonates of alkali and earth alkali metals. Thus, the hardening process takes place simultaneously in the two phases. The isocyanates react to a polymeric material, liberating CO2. This in turn acts as a catalyst for the setting of the alkali silicates, yielding an SiO2 gel and various carbonate phases as reaction products. Five different carbonates have so far been identified. The paper summarizes results obtained to date in a current research programme sponsored by the German Research Foundation for pure organo-mineral cements and some mortars made therefrom.

This chapter covers carbon–carbon bond formations based on addition of organotransition metal compounds (C–M) to CO (carbonyl compounds and carbon dioxide), CN (imines and isocyanates), and CN (nitriles and isocyanides) bonds. A series of reactions reported between 1993 and 2005 are discussed comprehensively. Not only reactions using a stoichiometric amount of an organometallic compound but also catalytic processes are included, even though their catalytic mechanisms are only postulated in most cases.

International audience; We studied the direct effects of CO, and related changes in seawater carbonate chemistry on marine planktonic organisms in a mesocosm experiment. In nine outdoor enclosures (similar to 11 m(3) each), the partial pressure of CO2 (pCO(2)) in the seawater was modified by an aeration system. The triplicate mesocosm treatments represented low (similar to 190 parts per million by volume (ppmV) CO2), present (similar to 410 ppmV CO2), and high (similar to 710 ppmV CO2) pCO(2) conditions. After initial fertilization with nitrate and phosphate a bloom dominated by the coccolithophorid Emiliania huxleyi occurred simultaneously in all of the nine mesocosms; it was monitored over a 19-day period, The three CO2 treatments assimilated nitrate and phosphate similarly. The concentration of particulate constituents was highly variable among the replicate mesocosms, disguising direct CO2-related effects. Normalization of production rates within each treatment, however, indicated that the net specific growth rate of E. huxleyi, the rate of calcification per cell, and the elemental stoichiometry of uptake and production processes were sensitive to changes in pCO(2). This broad influence of CO2 on the E huxleyi bloom suggests that changes in CO2 concentration directly affect cell physiology with likely effects on the marine biogeochemistry.

Aims The extent of lymph node dissection in gastric cancer remains controversial. The Maruyama computer model and the sentinel lymph node biopsy (SLNB) are compared for their value to predict the nodal status and lead to stage-adapted surgery. Methods Thirty four patients with stage I–IV gastric cancer underwent both staging procedures. For SLNB, 15 patients underwent endoscopic, peri-tumoural injection of 99m Tc-colloid, and 19 patients were injected of Patent blue V ® . All ‘hot’ or blue sentinel lymph nodes (SLNs) were separately excised and histopathologically assessed. If the SLN was negative after routine staining by H&E, it was processed completely and reanalysed after immunohistochemistry. Results At least, one SLN was detected by means of SLNB in 33/34 of the patients. The sensitivity to identify a positive nodal status was 22/33 and the specificity/positive predictive value was 10/10 and 22/22. Additional micrometastases or isolated tumour cells in the SLN led to ‘upstaging’ of 5/15, initially classified as nodal negative by H&E-staining. Using the Maruyama computer model, a sensitivity of 22/23 for the correct prediction of the lymph node involvement was associated with a specificity of 2/10 and a positive predictive value of 22/30. Conclusions The clinical impact of the Maruyama computer model is limited due to low specificity and a low positive predictive value, rendering the method less useful as an indicator for individualised surgery.

Background The value of sentinel node biopsy in visceral cancers is uncertain. We evaluated the feasibility and utility of radiocolloid lymphatic mapping and selective lymph node sampling in patients with rectal cancer. Methods Forty-eight patients with rectal cancer were investigated. Thirty-seven patients had already undergone preoperative radiochemotherapy for locally advanced tumors. Eleven patients underwent primary surgery. An endoscopic injection of 1 mL technetium 99m–sulfur-colloid into the peritumoral submucosa was performed 15 to 17 hours before surgery. Ex vivo identification of the nuclide-enriched “sentinel lymph nodes” (SLNs) was performed using a hand-held γ-probe. The selected SLNs were then carefully and systematically examined using serial sections and immunohistochemistry. Results One or more SLNs were found in 46 of the 48 patients. The SLN detection rate was 96%. Sixteen of the 48 patients had lymph node metastases (35%). In 7 of the 16 patients, the SLNs correctly represented the nodal status. In 9 of the 16 patients, the SLN was tumor-free whereas non-SLN harbored metastases. This result represents a sensitivity of only 44%, and a false-negative rate of 56%. Further analysis showed that the method correctly predicted the nodal status only in the small subgroup of 5 patients with early cancer without preoperative radiation. In 4 patients, juxtaregional lymph nodes were excised on the basis of intraoperative radiocolloid detection, leading to upward staging in 1 patient. Conclusions Sentinel lymph node biopsy using the radiocolloid technique with ex vivo lymph node identification shows a relatively high detection rate; however, the sensitivity in patients with locally advanced/irradiated rectal cancer is low. Nevertheless, the detection of juxtaregional metastases can improve staging in some patients. Further studies should focus on patients with early rectal cancers where the data were more promising.

This paper describes research in which the behavior of ordinary concrete and high strength concrete under chemical attack was studied during a period of more than 5 years. The concrete specimens were immersed in a variety of chemical solutions (10, 5, 1, and 0.1% ammonium nitrate), and simultaneously subjected to different flexural loads with load levels of 0, 30, 40, and 50% of their initial flexural strengths. The strength and mass changes of the concrete specimens, and the penetration depths of the attacking ammonium nitrate ions into the specimens, were measured. The influence of concentration level of the solution on the bending strengths of the concretes was studied and is discussed on the basis of experimental observations.

The results of kiloelectronvolt-electron degradation a and annealing experiments obtained on a-Si:H-based p-i-n solar cells are interpreted using models developed earlier for the degradation of a-Si:H films and are placed in the framework of an extended collection length model. The strong degradation of the short-circuit current and fill factor due to considerable kiloelectronvolt-electron irradiation can be explained quantitatively. This makes possible a crucial test of the validity of the mathematical models for the kiloelectronvolt-electron-induced effects developed so far. It is shown that the major part of these reversible changes can be attributed to bulk effects: interface properties do not have to be considered. Furthermore, the results of a detailed investigation of the thermal recovery of electron-degraded solar cells can be explained consistently. Some unresolved issues are discussed, and experiments to resolve these questions are proposed. >

A method is described which enables the group-separation of proteinaceous binding media from vegetable glues (carbohydrates), and simultaneous hydrolysis of the proteins in mixtures of both. The mixtures of the binders are suspended in aqueous-ethanolic solvent with the H+ form of a strong cation exchanger and treated at elevated temperature in sealed vials. The polypeptides are cleaved by H+-catalysed hydrolysis. On abstraction the amino acids are transformed into the ammonium ions by the protons, and the cations are adsorbed by the exchanger resin. The amino acids are removed from solution in this way, thus suppressing interfering reactions with other binders, e.g. humin formation with carbohydrates. Clear and colourless solutions were obtained with all mixtures of vegetable and animal glues. Two fractions can be obtained after separation of the solid resin from the liquid supernatant - the resin fraction with the adsorbed amino acids, and the aqueous-ethanolic solution with the carbohydrates. In each of these fractions the two classes of binder can be identified separately by GC-MS; this avoids the occurrence of unresolved GC peaks and superimposed mass spectra. The method has been used to identify the binder found between fabric layers of a Burgundian liturgical vestment of the Order of the Golden Fleece from the first half of the 15th century, the Cope of the Virgin Mary. With the aid of the GC pattern obtained, and the mass spectra of the main peaks, which were identified as glucopyranose anomers, the binding medium was identified as starch.

Dielectric loss spectra of glass-forming propylene carbonate and glycerol at temperatures above and below T_g are presented. By performing aging experiments lasting up to five weeks, equilibrium spectra below T_g have been obtained. During aging, the excess wing, showing up as a second power law at high frequencies, develops into a shoulder. The results strongly suggest that the excess wing, observed in a variety of glass formers, is the high-frequency flank of a beta-relaxation., submitted to Phys. Rev. Lett., 4 figures, revised version after referee reports

Results of a study carried out over a period of more than five years on the behaviour of concrete and high strength concrete under chemical attack are described. The specimens were immersed in a variety of chemical solutions, such as ammonium sulfate and ammonium nitrate, both in concentrations ranging from 0.1 per cent to 10 per cent. Strength and weight changes and depth of penetration of the attacking ammonium nitrate ions were measured and influence of the initial concrete strength and the concentration level of the aggressive solutions on the behaviour of the concrete specimens were evaluated. Both ammonium sulfate and ammonium nitrate solutions were found to be highly aggressive, with ammonium sulfate leading to an expansive type attack, and ammonium nitrate leading to a dissolution type attack. High strength of concrete and low concentration of aggressive chemicals provided the best resistance against sulfate attack. Depth of penetration of ammonium nitrate was found to be governed by the level of concentration of the solution and the quality of the concrete, with the relative strengths of concretes immersed to ammonium nitrate solution being very nearly proportional to the depth of penetration. This was true, irrespective of initial strengths, or concentrations of the aggressive solutions. 17 refs., 4 tabs., 19 figs.

The Xe adsorption on Al(110) at 45 K has been studied by UPS, TDS and LEED. The Xe-TD spectra at low coverage (θ(Xe) ⩽ 0.1 ML) consist of a single peak at 70.4 K, independent on the coverage, suggesting a first-order desorption kinetics. An activation energy of desorption of 0.19 eV/atom and a frequency factor of 5 × 1013 s−1 has been determined. Beyond a coverage of θ(Xe) = 0.1 ML a change to zeroth-order desorption kinetics is accompanied by the appearance of a Xe-induced LEED pattern suggesting the formation of Xe islands. The LEED pattern exhibits the same periodicity, perpendicular to the surface rows, as the Al(110) substrate and suggests Xe adsorption along the surface troughs with a Xe-Xe interatomic distance of 4.41 A. The Xe 5p 1 2 and 5p 3 2 photoemission peaks show two different characteristics as a function of the coverage. Below θ(Xe) = 0.1 ML the maximum of the 5p 1 2 signal occurs at about 0.2 eV lower energy than above 0.1 ML. Only beyond θ(Xe)=0.1ML the 5p 3 2 peak exhibits mj-splitting. All these observations are interpreted in terms of a 2D phase transition: 2D-gas (θ(Xe) ⩽ 0.1 ML) ↔ 2D-solid (0.1 ⩽ θ(Xe) ⩽ 1 ML).