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Background and aims The Hepatitis E virus hijacks the endosomal system for its release. These structures are highly dependent on cholesterol. Hence, this study investigates the impact of HEV on cholesterol-metabolism, the effect of intracellular cholesterol content on HEV-release and the potential of cholesterol-modulators to serve as antivirals. Methods Intracellular cholesterol-content of cells was modulated and impacts on HEV were monitored using qPCR, Western blot, microscopy, virus-titration and density-gradient centrifugation. Blood-lipids and HEV-RNA were routinely quantified in chronically infected patients during follow-up visits. Results In HEV-infected cells, decreased levels of cholesterol are found. In patients, HEV infection decreases serum-lipid concentrations. Importantly, statin treatment herein increases viral titers. Similarly, reduction of intracellular cholesterol via simvastatin treatment increases viral release in vitro. On the contrary, elevating intracellular cholesterol via LDL or 25-hydroxycholesterol strongly reduces viral release due to enhanced lysosomal degradation of HEV. Drug-induced elevation of intracellular cholesterol via fenofibrate or PSC833 impairs HEV release via the same mechanism. Conclusions This study analyses the crosstalk between HEV and intracellular cholesterol. The results highlight the importance of an intact cholesterol homeostasis for HEV-release and thereby identify a potential target for antiviral strategies. Especially fenofibrate is considered a promising novel antiviral against HEV. Beyond this, the study may help clinicians evaluating co-treatments of HEV-infected patients with statins, as this may be counter indicated., Graphical abstract

First investigations focus on the usage, processing and material properties of polycarbonate (PC) based materials used in cable duct production. Test coupons were taken from in-situ cable ducts including further additives generally used in industry. Different mechanical and optical analytical methods were performed. Significant differences in tensile properties of polycarbonate/ acrylonitrile butadiene styrene (PC/ABS) compared to mineral reinforced PC were observed. The hardness of mineral reinforced PC is significantly dependent on the geometry of the cable ducts. The fracture behavior and morphology of the PC/ABS fracture surface is directly related to the coupon temperature during Charpy impact testing. The process temperature influences the failure behavior during high impact processing such as high speed punching. Due to the lower impact strength of mineral reinforced PC less film and burr formation compared to PC/ABS are likely. However, the mineral distribution is not homogeneous and therefore subject to further investigation. This study aims at a better understanding of process properties of PC/ABS products, parameter selection, quality improvement and general understanding of underlying microstructural and surface properties.

One of the process steps in the production of cable ducts is punching the side recesses. Polyvinyl chloride (PVC) has already been successfully processed using this method. Punching flame-retardant polycarbonate/acrylonitrile butadiene styrene (PC/ABS) cable ducts, on the other hand, is challenging. There is an increase in burr and film formation. Both reduce the quality of the end product and thus make an additional deburring process necessary. Using high-speed recordings and a transparent tool, this research attempts to visualize and adjust burr and film creation. This identifies the first burr and film formation. Then, if necessary, optimization steps can be defined. Because the returning punch effects the burr and film, analyzing the existing burr and film is false. In order to formulate optimization procedures, the existing punching processes for PVC and PC/ABS were compared. As a result, snapshots from the high-speed recordings were assigned to the process steps in question. This revealed the commencement of film development and its reasons, as well as the fact that PVC and PC/ABS shatter in various ways.

The neutral beam injection systems for the international fusion experiment ITER used for heating, current drive, and diagnostic purposes are based on RF-driven negative hydrogen ion sources with a source area of roughly 0.9 m × 1.9 m. The sources operate at 0.3 Pa in hydrogen and in deuterium using a total available RF generator power of 800 kW per source at a frequency of 1 MHz. In order to fulfill the challenging requirements for ITER and beyond (like a DEMOnstration power plant, DEMO), worldwide developments are underway addressing the topics of plasma generation, ion extraction together with the issue of reducing and stabilizing the co-extracted electron current, and the beam properties. At the example of the activities at the ITER prototype source and the size scaling experiment ELISE, the present status and its challenges are summarized. The RF power transfer efficiency of these sources is only about 65% in maximum, giving significant room for improvements to relax the demands on the RF generator and ensure reliable operation. The plasma uniformity in front of the large extraction system is the result of plasma drifts. They have a huge impact on the nonuniformity of the co-extracted electrons and influence the ions and thus the beam properties as well. Understanding the optics of such large beams composed of hundreds of beamlets is a crucial task and is under continuous improvement. The main challenge, however, is still the fulfillment of the ITER requirements for deuterium, in particular, for long pulses. The management of caesium, which is evaporated into the source to generate sufficient negative ions by the surface conversion process, is one of the keys for stable and reliable operation.

Multiple small molecule immune modulators have been identified as synergistic with immune checkpoint blockade (ICB) in their effects on T lymphocytes , but are limited in their successful application to combination cancer immunotherapy due to their short in vivo retention and lack of affinity for T cells. We engineered an antibody-nanoparticle conjugate (ANC) platform consisting of 30 nm polymer nanoparticles that, due to their size and formulation, efficiently distribute after administration to lymph nodes, tissues highly enriched in lymphocytes that contribute to tumor control mediated by ICB. Displaying monoclonal antibodies against surface-expressed T cell markers, NP delivery in vivo to circulating and lymph node-resident lymphocytes was substantially enhanced, as was delivery of small molecules formulated into the NP by passive encapsulation . Using ICB monoclonal antibodies as both targeting moiety and signal-blocking therapeutic, ANCs improved the local and systemic anti-tumor effects of small molecule TGFβ receptor 1 inhibitor and an adenosine 2A antagonist when administered either locoregionally or systemically into the circulation in two syngeneic , aggressive tumor models, slowing tumor growth and prolonging animal survival. As these benefits were lost in the absence of ANC targeting, co-formulation strategies enabling the targeted co-delivery of multiple immunotherapeutics to T lymphocytes have high potential to improve ICB cancer immunotherapy by concurrent inhibition of non-redundant suppressive pathways.

The calcium aluminate electride [Ca24Al28O64]4+(e−)4 (C12A7:e−) is chemically and thermally stable in ambient atmosphere, offers strong electron donating capabilities and exhibits an intrinsic work function of 2.4 eV. Thus, it is an attractive material for electron emitter and low work function applications. For an implementation in negative hydrogen ion sources, where the electride could serve as a converter surface for the H− production, compatibility with moderate vacuum conditions and exposure to low pressure low temperature hydrogen plasmas must be ensured. Hence, the stability and work function performance of a polycrystalline C12A7:e− sample are investigated under ion source relevant vacuum (∼10−6 mbar) and plasma conditions (electron temperature ∼2 eV, electron density ∼1016m−3). The work function is measured via the photoelectric effect, showing that long-term hydrogen plasma exposure results in a steady-state surface work function of 2.75±0.10 eV. Since the electride is very sensitive to surface contaminations, an increase of the surface work function occurs as soon as the plasma is switched off. Vacuum heat treatment of the degraded C12A7:e− surface after plasma activation leads to a work function minimum of 2.9 eV for temperatures in the range of 670-770 K. Exceeding a temperature of ∼770 K leads to an increase of the C12A7:e− surface work function. The sample is stable during long-term hydrogen plasma exposure (up to 10 h total plasma-on time tested) and no plasma-induced erosion is observed.

The development of ion sources for NNBI systems at future fusion devices like ITER or DEMO is based on the surface production of negative hydrogen ions. Thus, low work function converter surfaces are mandatory. Besides the state-of-the-art technique of continuous Cs injection during ion source operation, alternative materials are desirable to overcome the drawbacks of volatile Cs coatings. In this work, a C12A7 electride material is studied regarding the work function behavior in a hydrogen and deuterium plasma environment at ion source relevant conditions. The minimum measured work function obtained during the campaign is 2.9 ± 0.1 eV, with an optimization potential to lower values at better vacuum conditions and higher annealing temperatures. Biasing the sample during plasma operation exhibits a strong impact on the work function performance, which is dependent on the polarity and the applied bias potential. The minimum work function obtained for the C12A7 electride used in this experiment is substantially higher than what is achieved with in situ caesiation (~ 2 eV), but the sample has demonstrated promising properties in terms of plasma resilience.

Atom transfer radical coupling (ATRC) reactions assisted by radical traps were studied under various conditions, with the extent of coupling of polymer chains monitored as a function of time. When using a radical trap that tended to aggregate into dimers, such as 2-methyl-2-nitrosopropane (MNP), the rate of coupling was enhanced when conditions were adjusted to favor its de-aggregation to the monomeric form: less polar solvent mixtures and/or the addition of β-cyclodextrin (β-CD). With radical traps that did not aggregate, such as nitrosobenzene (NBz) and N - tert -Butyl-α-phenylnitrone (tBuPN), coupling was generally accelerated under conditions consistent with higher K ATRP values. MALDI-TOF analysis was used to confirm the incorporation of the radical trap into the polymer dimers, supporting the mechanistic pathway proposed for radical trap-assisted ATRC. The effect of aggregation of the radical trap was further probed by using fractional equivalents of NBz in the coupling reaction, with a full equivalent leading to end-capped polymer chains that were unable to dimerize. By reducing the equivalents of NBz, the extent of coupling could be controlled by the temperature, with higher temperatures (80 °C) allowing ATRC to compete with RTA-ATRC and higher extents of coupling were observed.

We introduce the facile synthesis of fluorescent single-chain nanoparticles (SCNPs) based on chain-shattering acyclic diene metathesis (ADMET) polymers featuring self-immolative azobenzene motifs. An electrophilic alkoxyetherification is utilized to introduce the photoreactive moieties required for the subsequent chain collapse via UV-induced nitrile imine-mediated tetrazole-ene cycloaddition (NITEC).

We pioneer the synthesis of fluorescent single chain nanoparticles (SCNPs) via UV-light induced folding based on tetrazole chemistry directly in pure water. Water-soluble photoreactive precursor polymers based on poly(acrylic acid) (PAA) bearing tetrazole, alkene and tetraethylene glycol monomethyl ether moieties, (PAAn(Tet/p-Mal/TEG)), or simply tetrazoles moieties, PAAn(Tet), were generated via RAFT polymerization. While tetrazole, ene, and acrylic acid containing polymers fold via dual nitrile imine-mediated tetrazole-ene cycloaddition (NITEC) as well as nitrile imine-carboxylic acid ligation (NICAL), tetrazole and acrylic acid only functional prepolymers fold exclusively via NICAL. A detailed study of the underpinning photochemistry of NITEC and NICAL is also included. The resulting water-soluble SCNPs were carefully characterized via analytical techniques such as NMR, UV–vis, and fluorescence spectroscopy, as well as SEC and DLS.

Summary Due to its generality, the solvation model COSMO-RS can be used for a priori predictions of thermodynamic data for short-lived reactive species. In this paper, a strategy is outlined how COSMO-RS results can be employed as input in process simulations of reactive multiphase systems. As an example, the applicability of the method is demonstrated on prediction of partition coefficients for AIBN and corresponding azo-radicals between aqueous and organic phases.

Previous tensile tests at 50, 100 and 400 mm/min using standard polycarbonate/acrylonitrile butadiene styrene (PC/ABS) material qualities have led to the suspicion that strain at break decreases with increasing test speed. Here, the plastic deformation component is regarded as the main burr cause. Thus, higher process speeds during punching would lead to less burr formation. This thesis was proven by high-speed tensile tests with a self-developed test rig operating at a test speed of 36.000 mm/min. Both, pure standard materials, provided by a polymer granules supplier, and customized materials were investigated. The customized materials contain unknown additives generally used in industry, e.g. fillers. All samples were taken laterally from in-situ cable ducts. The remaining plastic strain was introduced as material parameter to compare the results of high-speed and conventional tensile tests. The investigations show that the remaining plastic strain which is understood as the major burr cause decreases with increasing test speed. Furthermore, the mean values of the remaining plastic strain of the individual materials converge when exposed to higher test speeds. This leads to the thesis that one tool configuration can be used for different polycarbonate (PC) based materials presumed the process speed is adjusted correctly.

We introduce a mild and efficient avenue to induce the folding of single chain polymer nanoparticles (SCNPs) using visible light. The versatility of the method is based on three folding mechanisms exploiting tetrazole chemistry, i.e., nitrile imine-mediated tetrazole-ene cycloaddition (NITEC), nitrile imine carboxylic acid ligation (NICAL) as well as nitrile imine self-dimerization. To our knowledge, this visible light driven approach is the to-date mildest avenue to fold single polymer chains into compact particles using light.

A high-gain source follower, utilizing oxide TFTs with a Corbino (circular) structure, is reported. Given the infinite output resistance exhibited by Corbino TFTs in the outer-drain condition (i.e., when the outer electrode is biased as the drain), the Corbino TFT-based source follower provides higher gain in operation than its rectangular TFT-based counterparts.

We studied the environmental stability of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) with single-layer (SiO2) and bilayer (SiO2/SiN x ) passivation under high-humidity (80%) storage. During the 30 days of investigation, all single-layer passivated TFTs showed negative turn-ON voltage shifts ( $\Delta V_{\mathrm{{\scriptstyle ON}}}$ ), the size of which increased with storing time. The negative $\Delta ~V_{\mathrm{{\scriptstyle ON}}}$ is attributed to donor generation inside the active a-IGZO caused by the diffusion of ambient hydrogen/water molecules passing through the SiO2 passivation layer. The X-ray photoelectron spectroscopy depth profile for the SiO2 passivated structures confirms that the concentration of oxygen vacancies, which is initially larger at the a-IGZO/SiO2 interface, compared with the bulk a-IGZO, decreases after 30 days of storage under high humidity. This can be explained as the passivation of oxygen vacancies by diffused hydrogen. On the other hand, all bilayer passivated TFTs showed good air stability at room temperature and high humidity (80%).

// Rahel Philip 1 , Sarah Heiler 1 , Wei Mu 1 , Markus W. Buchler 2 , Margot Zoller 1 and Florian Thuma 1 1 Department of Tumor Cell Biology, University Hospital of Surgery, Heidelberg 2 University Hospital of General Surgery, Heidelberg Correspondence: Florian Thuma, email: // Margot Zoller, email: // Keywords : Colorectal cancer, claudin 7, EpCAM, cancer initiating cells, metastasis Received : September 15, 2014 Accepted : December 02, 2014 Published : December 03, 2014 Abstract In colorectal cancer (CoCa) EpCAM is frequently associated with claudin-7. There is evidence that tumor-promoting EpCAM activities are modulated by the association with claudin-7. To support this hypothesis, claudin-7 was knocked-down (kd) in HT29 and SW948 cells. HT29-cld7 kd and SW948-cld7 kd cells display decreased anchorage-independent growth and the capacity for holoclone-, respectively, sphere-formation is reduced. Tumor growth is delayed and cld7 kd cells poorly metastasize. In line with this, migratory and invasive potential of cld7 kd clones is strongly impaired, migration being inhibited by anti-CD49c, but not anti-EpCAM, although motility is reduced in EpCAM siRNA-treated cells. This is due to claudin-7 recruiting EpCAM in glycolipid-enriched membrane fractions towards claudin-7-associated TACE and presenilin2, which cleave EpCAM. The cleaved intracellular domain, EpIC, promotes epithelial-mesenchymal transition (EMT)-associated transcription factor expression, which together with fibronectin and vimentin are reduced in claudin-7 kd cells. But, uptake of HT29 wt and SW948 wt exosomes by the claudin-7 kd lines sufficed for transcription factor upregulation and for restoring motility. Thus, claudin-7 contributes to motility and invasion and is required for recruiting EpCAM towards TACE/presenilin2. EpIC generation further supports motility by promoting a shift towards EMT. Notably, EMT features of cld7-competent metastatic CoCa cells can be transferred via exosomes to poorly metastatic cells.

Urbochargers are important components to minimize the petrol consumption of modern gasoline engines. The temperature in the turbocharger housings can reach until1.050 °C. Due to this reason, high heat resistant stainless steel, like the material DIN1.4848 with a high quantity of nickel (up to 25 %) and chrome (up to 20 %) is used in this application. During metal cutting operations the temperature at the cutting edge will increase due to the high quantity of nickel and the abrasive wear will be created by the chrome carbides within the cast material. The material hardness can increase by the machining process. Drilling and threading are one of the most critical machining operations in this material, because a huge frication area exists between the material and the tool. This provokes a high friction and the possibility of built-up-edge at the cutting edge which provides the rapid wear of the tool. In this part of the development project the tool life of different threading tools was analyzed. Taps in HSS-Co-PM and solid carbide were available for the tool life tests. The possibility to use the cold forming technology for threading was also analyzed. The strength of the internal threads was tested with pull out tests according DIN 898-2.

A rapid and cost-effective lithographic method, polymer blend lithography (PBL), is reported to produce patterned self-assembled monolayers (SAM) on solid substrates featuring two or three different chemical functionalities. For the pattern generation we use the phase separation of two immiscible polymers in a blend solution during a spin-coating process. By controlling the spin-coating parameters and conditions, including the ambient atmosphere (humidity), the molar mass of the polystyrene (PS) and poly(methyl methacrylate) (PMMA), and the mass ratio between the two polymers in the blend solution, the formation of a purely lateral morphology (PS islands standing on the substrate while isolated in the PMMA matrix) can be reproducibly induced. Either of the formed phases (PS or PMMA) can be selectively dissolved afterwards, and the remaining phase can be used as a lift-off mask for the formation of a nanopatterned functional silane monolayer. This “monolayer copy” of the polymer phase morphology has a topographic contrast of about 1.3 nm. A demonstration of tuning of the PS island diameter is given by changing the molar mass of PS. Moreover, polymer blend lithography can provide the possibility of fabricating a surface with three different chemical components: This is demonstrated by inducing breath figures (evaporated condensed entity) at higher humidity during the spin-coating process. Here we demonstrate the formation of a lateral pattern consisting of regions covered with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) and (3-aminopropyl)triethoxysilane (APTES), and at the same time featuring regions of bare SiOx. The patterning process could be applied even on meter-sized substrates with various functional SAM molecules, making this process suitable for the rapid preparation of quasi two-dimensional nanopatterned functional substrates, e.g., for the template-controlled growth of ZnO nanostructures Bauermann, L. P.; Gerstel, P.; Bill, J.; Walheim, S.; Huang, C.; Pfeifer, J.; Schimmel, T. Langmuir 2010, 26, 3774–3778. doi:10.1021/la903636k.

Purpose: To estimate changes in the 23Na density and in the 23Na relaxation time T2* in the anatomically small murine brain after stroke. Materials and Methods: Three-dimensional acquisition weighted chemical shift imaging at a resolution of 0.6 × 0.6 × 1.2 mm3 was used for sodium imaging and relaxation parameter mapping. In vivo measurements of the mouse brain (n = 4) were performed 24 hours after stroke, induced by microinjection of purified murine thrombin into the right middle cerebral artery. The measurement time was 14 minutes in one mouse and 65 minutes in the other three. An exponential fit estimation of the free induction decay was calculated for each voxel enabling the reconstruction of locally resolved relaxation parameter maps. Results: The infarcted areas showed an increase in sodium density between 160% and 250%, while the T2* relaxation time increased by 5%–72% compared to unaffected contralateral brain tissue. Conclusion: 23Na chemical shift imaging at a resolution of 0.6 × 0.6 × 1.2 mm3 enabled sodium imaging of the anatomical small mouse brain and the acquired data allowed calculating relaxation parameter maps and hence a more exact evaluation of sodium signal changes after stroke. J. Magn. Reson. Imaging 2011;. © 2011 Wiley-Liss, Inc.

A major challenge in constructive nanolithography is the preservation of the lateral resolution of a monolayer-thick template pattern while amplifying it to a structure with a thickness above 10 nm. So far, the most successful approach to achieve this is surface-initiated polymerization (SIP) from e-beam structured monolayer templates in a multistep process. However, spreading of the polymer on the substrate leads to a rapid line-widening. Therefore, structures with lateral resolutions well below 100 nm and thicknesses above 10 nm (aspect ratio: 0.1) were not reported yet. Our approach of photoinduced, constructive, reversible nanolithography, is based on nanografting within a coumarin-derivative thiol (CDT) solution using the tip of an atomic force microscope (AFM). By photodimerization and the formation of disulfide bonds, the CDT polymerizes in a single-step process. We demonstrate the highest lateral resolution in constructive nanolithography at thicknesses above 10 nm (40 nm lateral resolution at 12 nm thickness, aspect ratio: 0.3).

The local structure of thin CoO films grown on a single crystal Au(1 1 1) surface has been studied by Auger electron diffraction (AED). Therefore, the angular dependence of the Auger electron intensity of Co-LMM and O-KLL Auger electrons was recorded in the total half-space above the film. Such 2π-scans immediately reflect the symmetry of the surface and the local structure of the film. The experimental data are compared to multiple-scattering cluster calculations, where both the influence of multiple-scattering effects and effects of Auger transition matrix elements have been investigated. We have found that the AED patterns of a CoO film in forward-scattering conditions do not always provide straightforward information on the local structure of the film, whereas the multiple-scattering approximation applied gives very good agreement between experimental and theoretical results.

Using Auger electron spectroscopy we have studied the growth of cobalt oxide on Ag(1 0 0) substrate at different substrate temperatures (25, 170 and 250 °C). The films grown at 170 °C substrate temperature were found to grow closest to a layer-by-layer growth mode. In order to experimentally investigate the electronic structure of the CoO films angle-resolved UV photoelectron spectra were recorded for a 10 ML CoO film that are discussed and compared with available experimental results.

Angle-resolved ultraviolet photoemission spectroscopy has been used to study thin layers of Co and CoO on an Au(1 1 1) substrate. A bulk-like CoO layer was obtained for a nominal coverage of 7 ML Co, with Co evaporated in an oxygen atmosphere of 10 −4 Pa and the Au(1 1 1) substrate at 350 K. Low-energy electron diffraction of this layer exhibits a (1 × 1) structure, indicating an unreconstructed CoO(1 1 1) surface. Considering the instability of a bulk-like terminated CoO surface, we assume stabilization by OH termination. At low coverage, the CoO layer is oxygen deficient and exhibits metallic character. For the bulk-like CoO layers we found band-like oxygen states and no detectable dispersion for the states near the Fermi edge, which is in agreement with previous investigations of single-crystalline CoO.

Extracts from a silicone rubber product were characterized by gel-permeation chromatography (GPC), matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry, Fourier transform infrared spectroscopy (FT-IR), electrospray time-of-flight (ESI-ToF) mass spectrometry and gas chromatography/mass spectrometry (GC/MS). The extracted sample was determined to be a complex mixture with a molecular weight ranging from 200 to 210,000 Da as determined from GPC measurements. GPC fractions of the extract sample were further analyzed by MALDI-ToF mass spectrometry, ESI-ToF mass spectrometry, FT-IR spectroscopy and GC/MS. The extracted products were determined to be macrocyclic poly(dimethylsiloxane) oligomers. Two additives known as bis(2-ethylhexyl) adipate and bis(2-ethylhexyl) phthalate were observed in the extract.

We have prepared ordered thin films of CoO by evaporating cobalt in an O2 atmosphere on to a heated (500 K) Ag(100) substrate. The geometric and electronic structure of the films was characterized by means of Auger electron diffraction (AED) and angle-resolved photoemission spectroscopy (ARUPS), respectively. The experimental AED results were compared with simulated data, which showed that the film grows in (100) orientation on the Ag(100) substrate. Synchrotron-radiation-induced photoemission investigations were performed in the photon energy range from 25 eV to 67 eV. The dispersion of the transitions was found to be similar to that of previous results on a single-crystal CoO(100) surface. The resonance behaviour of the photoemission lines in the valence-band region was investigated by constant-initial-state (CIS) spectroscopy. The implications of this behaviour for assignment of the photoemission lines to specific electronic transitions is discussed and compared with published theoretical models of the electronic structure.

Application of Aroma Extract Dilution Analysis to the volatiles generated from the degradation of 9-hydroperoxy-(E,Z,Z)-10,12, 15-octadecatrienoic acid under aqueous acidic conditions at room temperature, and in the presence of butter starter cultures, showed that the metallic-smelling (E,Z)-2,6-nonadienol (NDOH) was the most odour-active compound. Quantitative studies on its generation during storage of sweet-cream buttermilk which had been spiked with several potential precursors, suggested the following reaction pathway for the formation of NDOH during the manufacture of buttermilk: during fermentation of the sweetcream, the α-linolenic acid present in the neutral triacylglycerides is peroxidized by lipoxygenases of the starter cultures into glyceryl 9-hydroperoxy-(E,Z,Z)-10,12,15-octadecatrienoate. During separation of the butterfat, the polar peroxide is transferred into the buttermilk and is subsequently cleaved into (E,Z)-2,6-nonadienal under the acidic conditions in the buttermilk matrix. Reductases of the starter cultures, which are still active during storage, finally produce (E,Z)-2,6-nonadienol and the attendant metallic off-flavour.

Slow positrons were used to study buried open-volume defects in epitaxially grown Cu and Ag overlayers on Ru(0001). Vacancy complexes (voids) were found after cryo-condensation of thick (100 nm) Cu and Ag films. These complexes anneal below room temperature. An Ar-sputtered Ru(0001) surface was covered with a 32 nm Cu overlayer (deposition at 300K). The buried defect layer was studied in the as-deposited and as-annealed state as well. It was found that the defect concentration in the Cu layer is distinctly increased after annealing at 500 K. Thus, migration of sputter defects towards the surface through the epitaxially grown metallic overlayer is directly observed.

In addition to the inverse lifetime, the photoemission peak width of a surface state depends on the quality of the surface. For a stepped surface, in particular, there is an energy shift of the surface state owing to the confinement of electrons. A random distribution of steps causes an asymmetric peak broadening, which is examined as a function of the shift parameter, the inverse lifetime and the mean terrace width. The model is discussed for the Cu(111) sp-surface state for which an influence of steps on the peak shape is obtained particularly for mean terrace widths less than 100 A.

The model of randomly distributed steps is examined with respect to the possibility of non-lifetime broadening in photoemission spectra from sp-band surface states. The peak shape is discussed in terms of hole lifetime, terrace width, and angle of emission. The model calculations are based on the parameters of the Cu(111) sp-surface state.

The odour-active volatiles in fresh fermented sweet cream buttermilk, exhibiting a mild, sweet-buttery odour, and sour cream buttermilk in which a metallic odour note had been formed after a storage period of 4 d at 8°C, were compared on the basis of aroma extract dilution analyses. Among the 13 odorants detected in the sweet cream buttermilk sample, the coconut-like smelling γ- and δ-decalactone and δ-octalactone showed the highest flavour dilution (FD) factors. Nine of the 13 odorants present in the sweet cream buttermilk sample appeared with significantly higher FD factors in the sour cream buttermilk. Among them, 4,5-epoxy(E)-2-decenal, 3-methyl indol and (E)-2-undecenal showed the most significance increase. Ten additional odorants were detected in the sour cream buttermilk sample, among which the metallic smelling (E,Z)-2,6-nonadienol predominated with the highest FD factor. Sensory experiments suggest that the dienol, showing the low odour threshold of 0·07 ng/L in air and 1·3 μg/L in buttermilk, is the key flavour compound causing the metallic off-odour in stored sour cream buttermilk.

Dielectric nonlinearities in triglycine sulfate (TGS) have been measured by the analysis of harmonic components of the electric current, while a sinusoidal electric field was applied to the sample. From the nonlinear permittivities of second and third order in the paraelectric phase small bias fields can be evaluated. In the TGS sample a bias field in the order of 100 V/m with a temperature dependence according to a constant polarization of 8.5 μC/m2 was found. This result can be explained by fixed dipolar defects.

A series of phenylene-bridged bis-porphyrin adducts have been synthesized, containing one, two, or three phenyl bridges. Complete synthetic details are provided. For studies of photochemical electron transfer, mixed metals were incorporated, with zinc in one porphyrin macrocycle and Fe III (bis-imidazole) in the other macrocycle. When photoexcited, an electron is transferred from Zn to Fe III

Our work is aimed at enhancing the external quantum efficiency (EQE) of n-i-p photodiodes by reducing the absorption losses in the p-layer and the recombination losses in the p-i interface. We have applied boron-doped and undoped hydrogenated amorphous silicon carbon alloy (a-SiC:H) grown in hydrogen-diluted, silane-methane plasma to both the p-layer and undoped buffer layer, thus tailoring the p-i interface. The current-voltage, capacitance-voltage, and spectral-response characteristics of fabricated photodiodes are correlated with the doping level, optical band gap, and deposition conditions for a-SiC:H layers. The optimized device exhibits a leakage current of about 110 pA/cm2 at the reverse bias of 5 V, and a peak value of 89% EQE at a wavelength of 530 nm. At shorter wavelengths, the EQE decreases down to 56% at a 400 nm wavelength. Calculations of transmission/reflection losses at the front of the photodiode show that observed short-wavelength sensitivity enhancement can be attributed to improved separation of electron-hole pairs in the p-layer depletion region.

The maintenance of a gradient of potassium and sodium ions across the cell membranes is essential for the physiological function of the mammal organism. The measurement of the spatial distribution of pathologically changing ion concentrations of (23)Na and (39)K with magnetic resonance imaging offers a promising approach in clinical diagnostics to measure tissue viability. Existing studies were focused mainly on (23)Na imaging as well as spectroscopy with only one post-mortem study for (39)K imaging. In this paper a triple resonant RF coil setup for the rat head at 9.4T is presented for imaging of both nuclei ((23)Na and (39)K) and the acquisition of anatomical proton images in the same experiment without moving the subject or the RF coil. In vivo MR images of (39)K and (23)Na in the rat brain were acquired as well as anatomical proton images in the same scanning session.

Hydrogenated amorphous silicon (a–Si:H) n–i–p photodiodes are used as pixel sensor elements in large-area flat-panel detectors for medical imaging diagnostics. Accurate model of the sensor plays an imperative role in determining the performances of the detector systems as well as ascertaining design issues prior to production. This work presents the formulation of a compact model for segmented a–Si:H n–i–p photodiodes suitable for circuit-level simulation. The underlining equations of the model are based on device physics where the parameters are extracted from pertinent measurement results of previously fabricated a–Si:H n–i–p photodiodes. Furthermore, the implemented model allows photoresponse simulation with the addition of an external current source. Results of the simulation demonstrated excellent matching with measurement data for different photodiode sizes at various temperatures. The model is implemented in Verilog-A and simulated under Cadence Virtuoso design environment using device geometry and extracted parameters as inputs. The model formulation and parameter extraction process, as well as measurements and simulation results are presented.

This paper reports the first successful attempt to fabricate amorphous silicon (a-Si:H) n-i-p photodiodes on a thin stainless-steel foil substrate for medical X-ray imaging applications. Two architectures of the n-i-p-photosensor, where the top electrode is based on amorphous or polycrystalline ITO, have been developed and characterized. The impact of critical fabrication steps including the deposition of semiconductor layers, dry etch of the NIP stack, diode passivation and encapsulation, as well as a contact formation on the device performance is presented and discussed. The test structures comprising segmented photodiodes with an active area ranged from 0.126 × 0.126 to 1 × 1 mm2 have been fabricated on stainless-steel foils and on glass substrates for the purposes of process characterization. The fabricated samples are evaluated in terms of current-voltage, capacitance-voltage, and spectral response characteristics.

Hydrogenated amorphous silicon (a-Si:H) n-i-p photodiodes may be used as the pixel sensor element in large-area array imagers for medical diagnostics applications. The dark current level is an important parameter that dictates the performances of these types of pixelated imaging devices. Through measurements performed at different ambient temperatures, the leakage current components of segmented a-Si:H n-i-p photodiodes were extracted and analyzed. It was found that the central component of the reverse current depends exponentially on bias and temperature. The activation energy of this component is independent of bias. The peripheral component of reverse current exhibits linear bias dependence at temperatures up to 50°C, while the contribution of this component diminishes at high temperatures. The dependence of dark current components on bias and temperature could be described by compact analytical equations. The model of forward and reverse dark current characteristics in temperature range was implemented in Verilog-A hardware description language.

This paper describes the oil slick detection algorithm developed at FIMR as a part of the project “OILI”, oil spill detection in the Baltic Sea, co-funded by National Technology Agency of Finland (TEKES). The implementation of this algorithm will be part of the operational oil slick detection over the Baltic Sea located at SYKE. The algorithm first makes some file format conversions. Some pre-filtering for the image is then performed: zerovalued pixels outside the land mask are removed, segments with very high backscattering values are removed, optional scalloping filtering is performed and speckle filtering is performed. Also a coastal area mask is generated for each SAR image, and potential ships in the SAR image are located. A block diagram of the actual oil slick detection performed after the preprocessing stages is shown in Fig. 1. The slick detecFig. 1. Block diagram of the oil slick detection program. The input files are drawn in green color, program main functions are drawn in blue color, and the final outputs are drawn in yellow color. tion is based on thresholding the SAR and then computing segment-wise features for the dark areas (segments) produced by the thresholding. Based on the segment-wise features, a confidence level value for each segment is given, and this value is used in the classification. RADARSAT-1 ScanSAR SAR images have been used in the training and testing of the algorithm.

In this study we compare on-line gel permeation chromatography (GPC) electrospray ionization (ESI) time-of-flight (TOF) mass spectrometry (MS) to automated GPC matrix assisted laser desorption ionization (MALDI) TOF MS for poly (dimethylsiloxane) (PDMS) analysis. Average mass values for a hydroxyl-terminated PDMS (OH-PDMS) sample were obtained and compared to traditional GPC that was calibrated with narrow polystyrene standards, by direct ESI and MALDI MS analysis, by a summation of mass spectra of all GPC fractions, and also by the recalibration method determined by both mass spectrometric methods. Quantitatively, the difference noted here between these hyphenated techniques is that GPC-ESI-TOF MS effectively reports the low-mass oligomers and underestimates the high-mass oligomers, while GPC-MALDI-TOF MS effectively reports the high-mass oligomers and underestimates the low-mass oligomers. In the GPC-ESI-TOF MS experiments, ion current suppression was observed in the high molecular weight region. The suppression effect was confirmed by repeatable sample runs and by injecting different PDMS samples. Higher chromatographic resolution was observed for GPC-ESI-TOF MS compared to GPC-MALDI-TOF MS. In fact, truly mono-disperse oligomers were observed in the low molecular weight range from GPC-ESI MS experiments.

Two metal etch systems are compared in terms of their impacts on submicron transistor gate oxide integrity. The magnetically enhanced RIE (MERIE) system is shown to cause significant gate oxide damage with a pronounced radial dependence. This damage does not occur on wafers etched in the hexode-type RIE system. Experimental work on the MERIE system shows that the presence of the magnetic field during the aluminum overetch and barrier metal etch portion of the process is the primary cause for the observed gate oxide damage. This damage can be minimized by reducing or eliminating the magnetic field during the overetch step. >

We have prepared a series of bis-porphyrin molecules in which the angle between the donor and acceptor porphyrins is systematically varied. In these molecules, the intramolecular electron transfer rate varies by over 1 order of magnitude as the angle changes. This variance is anticipated by symmetry arguments which focus on the nodal properties of the molecules

In order to investigate the matrix effects of a hazardous waste landfill leachate in the analysis of priority pollutants by headspace gas chromatography, spiking experiments were performed (a) with the untreated leachate, (b) with the leachate after separation of oil and (c) with blanc water samples as a reference. A standard mixture containing volatile chlorinated hydrocarbons, benzene and alkylated benzenes (100–200 μg) were spiked into 50 ml-samples of (a)–(c). The samples were thermostated at 40°C for 20 min and analyzed by headspace GC. Serious matrix effects were observed for all reference compounds, resulting in significant enhancement or depression of the corresponding peak areas compared with the spiked water control samples. The data sets are discussed with respect to the contents of leachate oil and chloride. From the findings of this study, recommendations for the application of headspace analysis to leachates are given.

This article reports on a-Si:H-based low-leakage blue-enhanced photodiodes for dual-screen x-ray imaging detectors. Doped nanocrystalline silicon was incorporated in both the n- and p-type regions to reduce absorption losses for light incoming from the top and bottom screens. The photodiode exhibits a dark current density of 900 pA/cm2 and an external quantum efficiency up to 90% at a reverse bias of 5 V. In the case of illumination through the tailored p-layer, the quantum efficiency of 60% at a 400 nm wavelength is almost double that for the conventional a-Si:H n-i-p photodiode.

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