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Optical measurements reveal the preferential orientation of nanostructures within polymer films, which results from the fabrication process including mechanical and thermal treatments. As the wavelength of the incident light is generally much larger than the characteristic dimensions of the molecular arrangement in semi-crystalline or amorphous polymers, the optical signal originates not directly from the nanostructure of the polymers. Linear dichroism measurements were correlated with synchrotron radiation-based x-ray scattering data on commercially available polyetheretherketone (PEEK) thin films (12 to 50 μm). Annealing changed the structure of amorphous films to semi-crystalline ones associated with the measured linear dichroism. The intensity of the measured anisotropic signal depended on the film thickness. While for wavelengths between 450 and 1100 nm the transmission was higher when the polarizer was parallel to the machine direction, for larger wavelengths maximum transmission was observed with the polarizer perpendicular to the machine direction indicating excitations parallel and perpendicular to the PEEK molecule axis, respectively. Annealing PEEK films at temperatures between 160 and 240°C decreased the transmission at 540 nm by a factor of two, whereas the anisotropy remained constant. x-ray scattering revealed strongest anisotropy for a periodicity of 15 nm in the machine direction of the cast film extrusion process. The long-range order of amorphous and semi-crystalline entities can explain the x-ray scattering data and the related optical anisotropy of casted PEEK films.

Understanding and controlling the structural anisotropies of injection-molded polymers is vital for designing products such as cantilever-based sensors. Such micro-cantilevers are considered as cost-effective alternatives to single-crystalline silicon-based sensors. In order to achieve similar sensing characteristics,structure and morphology have to be controlled by means of processing parameters including mold temperature and injection speed. Synchrotron radiation-based scanning small- (SAXS) and wide-angle x-ray scattering techniques were used to quantify crystallinity and anisotropy in polymer micro-cantilevers with micrometer resolution in real space. SAXS measurements confirmed the lamellar nature of the injection-molded semi-crystalline micro-cantilevers. The homogenous cantilever material exhibits a lamellar periodicity increasing with mold temperature but not with injection speed. We demonstrate that micro-cantilevers made of semi-crystalline polymers such as polyvinylidenefluoride, polyoxymethylene, and polypropylene show the expected strong degree of anisotropy along the injection direction.

The formation of circular cone-shaped Ge islands (12\ifmmode^\circ\else\textdegree\fi{} cones) has been observed for the growth of eight monolayers of Ge on Si(001) at 700 \ifmmode^\circ\else\textdegree\fi{}C using Sb as a surfactant. The Ge cones are strained and grow pseudomorphically, adopting the Si lattice constant. They have a tilt angle of 12\ifmmode^\circ\else\textdegree\fi{} and are composed of [117]-, [105]-type, and all intermediate facets. The island-size distribution is peaked around a typical size of \ensuremath{\sim}300--400 \AA{}, which results from a formation process under equilibrium conditions for diffusion of the Ge atoms. Growth at lower temperatures down to 300 \ifmmode^\circ\else\textdegree\fi{}C with Sb as a surfactant results in epitaxial but very rough Ge films which show a high degree of disorder.

BACKGROUND: Current medical scores have limited efficiency and safety profiles to enable assignment to the most appropriate treatment site in patients with lower respiratory tract infections (LRTIs). We describe our current triage practice and assess the potential of a combination of CURB65 with proadrenomedullin (ProADM) levels for triage decisions. METHODS: Consecutive patients with LRTIs presenting to our emergency department were prospectively followed and retrospectively classified according to CURB65 and ProADM levels (CURB65-A). Low medical risk patients were further subgrouped according to biopsychosocial and functional risks. We compared the proportion of patients virtually allocated to triage sites with actual triage decisions and assessed the added impact of ProADM in a subgroup. RESULTS: Overall, 93% of 146 patients were hospitalised. Among the 138 patients with available CURB65-A, 17.4% had a low medical risk indicating possible treatment in an outpatient or non-acute medical setting; 34.1% had an intermediate medical risk (short-hospitalisation); and 48.6% had a high medical risk (hospitalisation). Fewer patients were in a low CURB65-A class (I) than a low CURB65 class (0,1) (17.4% vs. 46.3%, p >0.001). Mean length of hospitalisation was 9.8 days including 3.6 days after reaching medical stability. In 60.3% of patients, hospitalisation was prolonged after medical stability mainly for medical reasons. CONCLUSIONS: Current rates of hospitalisation are high in patients with LRTI and length of stay frequently extended beyond time of medical stabilization. The lower proportion of patients reclassified as low risk by adding ProADM to the CURB65 score might improve confidence in the triage algorithm.

The precise knowledge of the diffraction condition, i.e., the angle of incidence and electron energy, is crucial for the study of surface morphology through spot profile analysis low-energy electron diffraction (LEED). We demonstrate four different procedures to determine the diffraction condition: employing the distortion of the LEED pattern under large angles of incidence, the layer-by-layer growth oscillations during homoepitaxial growth, a G(S) analysis of a rough surface, and the intersection of facet rods with 3D Bragg conditions.

We have investigated the influence of a surfactant on the equilibrium surface morphology in the pseudomorphic regime of heteroepitaxial growth. At 700 \ifmmode^\circ\else\textdegree\fi{}C, 8 monolayers of Ge on Si(001) using Sb as surfactant form strained islands with a size of \ensuremath{\sim}300 \AA{}, allowing partial elastic relaxation. The surface morphology depends strongly on the Sb coverage and changes from islands with [117] facets at high Sb coverage via round, flat cones with an inclination angle of 12\ifmmode^\circ\else\textdegree\fi{} to islands rotated by 45\ifmmode^\circ\else\textdegree\fi{} with [105] facets formed during growth at low Sb coverage. The equilibrium conditions are verified by the reversible transition from [117] facets to 12\ifmmode^\circ\else\textdegree\fi{} cones initiated by a change of the surfactant coverage.

Classical biomarkers like C-reactive protein (CRP) or the leucocyte count are only inaccurate tools for predicting the severity of community-acquired pneumonia (CAP). Procalcitonin (PCT) was found to predict 28-day mortality in CAP (area under the curve (AUC) 0.8) similar to the combination of PCT and CRB65 score (AUC 0.83) [1]. Novel prognostic biomarkers, such as Pro-ET1 and MR-ProADM, were shown to correlate with CAP severity [2]. We aimed to compare the diagnostic accuracy to predict mortality and ICU admission of clinical severity scores, biomarkers and their combination.

The visualization of the vascular network is a prerequisite to understand the formation of cancerous tissue. Synchrotron radiation-based micro computed tomography (SR! CT) provides the necessary micrometer resolution, to image the vessels down to the 3 to 5 ! m wide capillaries, the contrast differences between vessels and surrounding tissue, however, are too weak. Thus, in the present study highly X-ray absorbing barium sulfate micro-particles, which cannot penetrate through healthy vessel walls, were injected into the vessels. The acquired tomography data show that the stained vessels of the tumor tissue have different morphology and density with respect to the surrounding healthy tissue. The vessels of the cancerous tissue often exhibit spiral shapes. The vascular structure of tumors differs from that of healthy tissue. To understand the formation of cancerous tissue, the vascular network of tumors should be uncovered down to the capillary level. Standard synchrotron radiation-based micro computed tomography (SRµCT) in absorption contrast mode provides the necessary micrometer resolution (1) even for centimeter-sized tumors (2). The visualization of a vessel tree, however, also requires sufficient contrast. Because the tissue consists mainly of water and low absorbing species, SRµCT does not lead to significant X-ray absorption differences between vessels and surrounding tissue. So, the successful application of absorption contrast tomography requires dedicated tissue preparation procedures including embedding (3) and erosion casting (4). The more common procedure is the use of staining materials such as the incorporation of barium sulfate into the vessels (1,2,5). The present study is based on the injection of a barium sulfate suspension with a grain size of 0.5 to 1 ! m and a concentration of 80 g/l via the left ventricle of the heart of mice under anesthesia using a peristaltic pump. The mice contained C51 or U87 tumors grown during two to three weeks until they clearly emerged to be easily extracted post mortem. The tumors were transferred to Eppendorf tubes filled with 4% formalin for fixation. For the tomography measurements at the beamline TOMCAT (SLS at PSI, Switzerland) using the photon energy of 18 keV (bandwidth 2% to 3%) the container was fixed on the high-precision manipulator that rotated the tumor from 0° to 180° in steps of 0.12° to record 1501 projections. It should be mentioned that continuous irradiation of the specimen caused the formation of bubbles. To master this serious problem, the shutter in front of the specimen was closed during CCD-readout. Hence, the irradiation could be interrupted by 0.1 s between the exposure periods of 0.3 s per projection. The conventional filtered back-projection algorithm served for the reconstruction. Because the specimen was significantly larger than the field of view, local tomography of the inner part was performed, which yielded relative local X-ray absorption coefficients. The 3D

We report advances and complementary results concerning a recently developed method for high-sensitivity grating-based x-ray phase-contrast tomography. In particular we demonstrate how the soft tissue sensitivity of the technique can be used to obtain in-vitro tomographic images of rat brain specimens. Contrary to our previous experiments with fixated specimen (chemically modified or formalin fixed), the present results on the rat's brain are closer to the in-vivo situation. The findings are particularly important from a clinical point of view, since a similar approach using three gratings can be implemented with more readily available x-ray sources, such as standard x-ray tubes. © 2009 IOP Publishing Ltd.

It was with great interest that we read the recent articleby Razvi et al. [1] about the influence of antithyroid-drugs(ATDs) on subsequent radioiodine (RAI) treatment, andthe conclusions regarding possible radioprotective me-chanisms. Earlier studies demonstrated both the negativeeffect of ATDs on thyroidal iodine uptake as well as onthe outcome after RAI treatment, leading to thehypothesis that low iodine uptake levels were responsiblefor the poor outcome of radioiodine therapy [2,3]. On theother hand, carbimazole has been found to inhibitperoxidase catalysed synthesis of oxygen free radicals,which are suggested to mediate cell damage in radio-iodine treatment [4]. However, thyrocyte protection fromacute lethal action of RAI mediated by oxygen free radicalin vivo has not been verified.In a recent study including more than 200 patients wefound simultaneous ATD medication negatively influ-enced the pre-therapeutic iodine uptake as well as theoutcome of RAI therapy [5]. However, the success rate ofRAI therapy significantly increased in patients with loweriodine uptake levels independently of the administrationof carbimazole. Therefore we conclude that the negativeeffect of ATDs on the outcome of RAI treatment is notdirectly due to reduced RAI uptake and our findingssupport the hypothesis put forward by Razvi andcolleagues concerning drug induced radioresistance ofATDs. Consequently further investigations should beaddressed not only to the level of radioiodine uptake butto the cellular mechanisms of action of ATDs inradioiodine mediated thyroiditis.

Besides surface chemistry, the surface roughness on the micrometer scale is known to dominate the wetting behavior and the biocompatiblity properties of solid-state materials. The significance of topographic features with nanometer size, however, has yet to be demonstrated. Our approach is based on well-defined Ge nanopyramids naturally grown on Si(001) using ultrahigh vacuum chemical vapor deposition, where the nanopyramid density can be precisely controlled by the growth conditions. Since the geometry of the nanopyramids, often termed dome clusters, is known, the surface roughness can be characterized by the Wenzel ratio with previously unattainable precision. Dynamic contact-angle measurements and adsorption of γ-globulin as a function of that ratio demonstrate the strong correlation between surface nanoarchitecture, on one hand, and wetting behavior and biocompatibility, on the other hand. Related x-ray photoelectron spectroscopy measurements reveal that potential changes of surface composition can be definitely excluded.

Al/InxGa1−xAs(001) diodes incorporating Si bilayers deposited under As or Al flux were fabricated by molecular-beam epitaxy on GaAs(001) wafers for 0.2

The growth of Ge on Si is strongly modified by surface active species called surfactants. While the effectiveness of Sb as a surfactant in forcing layer-by-layer growth of Ge on Si(111) and in creating a misfit adjusting dislocation network confined to the Si Ge-interface has been demonstrated in previous studies, the dynamic growth process on an atomic scale leading to this result is still unknown. The relevance of the stress on surface morphology and the growth mode of Ge on Si(111) is presented in a detailed in situ study by spot profile analysing low energy electron diffraction during the deposition. The change from islanding to layer-by-layer growth is seen in the oscillatory intensity variation of the (00)-spot. To relieve the strain the Ge-film forms a microscopically rough surface of small triangular and defect free pyramids in the pseudomorphic growth regime up to 8 monolayers. As soon as the pyramids are completed and start to coalesce, strain relieving defects are created at their base, finally arranging to the dislocation network. After the overgrowth of the dislocations the surface smoothes again showing a much larger terrace length. The periodic dislocation network at the interface gives rise to an elastic deformation of the surface, which results in a spot splitting in LEED. Thus, for the first time the dynamics of the formation of a dislocation network has been observed in situ during the growth process. Surprisingly, the dislocation network is already completed to 70% immediately after 8 monolayers of coverage, which is attributed to the micro-rough surface morphology, providing innumerous nucleation sites for dislocation.

The growth and the atomic structure of the Ge on the Si(111)‐((3)1/2×(3)1/2)R30° surface are investigated by scanning tunneling microscopy. The coexistence of the ((3)1/2×(3)1/2)R30° and the c(2×4) reconstruction at the Si‐substrate is discussed. Germanium on silicon, usually indistinguishable from the silicon is identified on the boron induced ((3)1/2×(3)1/2)R30° surface using the difference in reconstruction of the substrate and epitaxial material. The germanium deposit shows a dimer adatom stacking fault‐like structure while the substrate still remains ((3)1/2×(3)1/2)R30° reconstructed. A significant boron diffusion is only observed after annealing at 480 °C, which converts the island surface into a ((3)1/2×(3)1/2)R30° reconstruction.

The growth of in situ prepared germanium layers on Si(111)-(7 × 7) has been studied as a function of substrate temperature and coverage. At room temperature, Ge grows in irregular clusters arranged in an ordered array on the substrate and the (7 × 7) reconstruction is preserved. At elevated temperature, in the submonolayer range triangular islands form with preferred growth in [ 1 1 2] direction. The islands show Si-like (7 × 7) and (5 × 5) DAS reconstruction. Ge nucleates preferentially at step edges and at (7 × 7) domain boundaries. Coverages over 2 ML result in a completely (5 × 5) reconstructed layer. On substrate with a ( 3 × 3 ) R 30° adatom arrangement after boron segregation, the Ge epilayer also exhibits DAS reconstructions of the same kind found on the pure Si substrates. Above 4 ML the formation of 3D islands is observed, which show mainly (113) and (111) facets. The islands are relaxed and show a mixture of c(2 × 8), c(2 × 4), and (2 × 2) reconstructions known for bulk Ge(111), when they are grown below 450° C. At a higher deposition temperature a (7 × 7) reappears on top of the 3D islands. Defects emerging from the bulk have been imaged.

Summary A procedure is described for the establishment of barley cell suspension cultures of mesocotyl origin. Protoplasts were reproducible isolated from cell suspensions of 4 barley cultivars (including spring and winter types). Sustained protoplast divisions from 2 barley genotypes (‘Borwina’, ‘Golden Promise’) have been obtained in agarose solidified culture medium. Plating efficiency frequencies up to 5 % were achieved for both cultivars. The protoplast derived calli were similar in appearance to callus lines used for the establishment of suspensions and have not produced embryo-like structures or shoots.

The epitaxial growth of Cu multilayers on Ni(100) is investigated by high-resolution LEED and variable temperature STM. Particular emphasis is put on the quantitative characterization of the recently discovered strain relief mechanism via internal {111} faceting. This mechanism is associated with the occurrence of patterns of orthogonal stripes at the film surface. The complementarity of real space and reciprocal space techniques are used to determine quantities such as stripe height, width and density with high accuracy. The pros and cons of local real space and integral reciprocal space techniques are discussed in detail.

The mechanisms of strain relief in submonolayer heteroepitaxy of Cu/Ni(100) are studied using variable temperature scanning tunneling microscopy and high resolution low energy electron diffraction. It is demonstrated that pseudomorphic copper islands, as they grow in size, undergo a spontaneous shape transition. Below a critical island size of about 500 atoms the islands have a compact shape, while above this size they become ramified. The shape transition of the coherently strained islands, predicted theoretically by Tersoff and Tromp, is driven by the size-dependent outward relaxation of the step edge atoms due to the positive lattice mismatch. The ramified island shape, which reflects the energy minimum of binding and strain energy, is characterized by only one parameter: the arm width of the monolayer-high copper islands w = (22 +/- 1) atoms.

A novel mechanism for ramified island growth in the initial stages of metal heteroepitaxy is reported. Scanning tunneling microscopy measurements reveal that copper islands on Ni(100), as they grow in size, undergo a shape transition. Below a critical size of approximate to 480 atoms, compact islands form, while above this size they develop a ramified shape. This effect is not of kinetic origin and has been observed in an extended range of growth temperature (250-370 K) and deposition Aux (10(-5)-10(-2) monolayer/s). The shape transition is ascribed to the island size dependent strain relaxation.

Micrometer-thin polymer films are often prepared using spin coating. In applications such as low-voltage dielectric elastomer actuators (DEAs), however, nanometer-thin polymer layers are required. In this paper, it is demonstrated that alternating current electrospray deposition allows for the fabrication of high-quality nanometer-thin polydimethylsiloxane (PDMS) films. The growth of the PDMS with an average molecular weight of 6000 g mol−1 at rates of 0.02–5.54 nm s−1 was in situ monitored by means of spectroscopic ellipsometry. The Cauchy layer model performs above a deposition-rate-dependent average film thickness, which is associated with a confluent film. The droplet size measurements as the function of deposition rate show that inertia and polarization forces dominate in liquid PDMS electrospraying. The roughness of the deposited films increases with the spray rate. After UV-light curing under Ar atmosphere, however, the films smoothen to root-mean-square roughness values between 0.20 and 0.28 nm determined by atomic force microscopy on areas of 5; μm; × 5; μm and between 2 and 20 nm determined by; interferometry on an area of 0.72 mm2. Such electrosprayed PDMS films with; (sub-)nanometer roughness qualify for the fabrication of low-voltage DEAs.

The initial stages of carbon alloying into the Si(001) surface are studied by scanning tunneling microscopy (STM) and density functional theory. Carbon increases the surface roughness compared to the clean surface and induces a c(4 × 4) reconstruction. To explain experimental observations, we propose a novel surface reconstruction model that involves pairing of Si dimers mediated by the presence of a complex of a C dimer and four nearest neighbor subsurface C atoms. The model is backed by total energy and thermal stability simulations. Its calculated surface charge density agrees well with the filled state STM images.

A detailed study of the nucleation and growth of Cu on Ni(100) as a function of substrate temperature and deposition rate by variable temperature STM is reported. By the quantitative analysis of the saturation island density as a function of temperature and flux for submonolayer coverages, we have deduced the migration barrier (0.35 eV), the dimer bond energy (0.46 eV) as well the sizes of the the critical nuclei. Because the dimer bond energy is large with respect to the migration barrier, a well-defined transition from a critical nucleus of 1 to 3 has been observed, as expected from the adsorption site geometry on square lattices. The large dimer bond energy of Cu on Ni(100) is one of the physical reasons for the recently uncovered strain relief mechanism via internal {111} faceting. The substantially increased island density on mono-and bilayer copper films on Ni(100) with respect to multilayer films might also be attributed to the enhanced lateral bonding.

Deposition of submonolayer coverages of C on Si(100) prior to Ge growth leads to the formation of Ge quantum dots below the critical thickness for Ge islanding on bare Si(100). In situ scanning tunneling microscopy reveals a high density of irregularly shaped islands for Ge coverages from 2.5 to 4 ML. Island sizes are broadly distributed between 10 and 25 nm. Keeping the C coverage constant and increasing the Ge coverage from 2.5 to 4 ML, the islands increase in height but their density remains constant (∼1011 cm−2). At a Ge coverage of 5.8 ML, formation of larger (105)-faceted islands is observed. Their density is reduced by a factor of 4 compared to smaller Ge coverages. Transmission electron microscopy shows that the nonfaceted islands are preserved after Si capping.

The human brain is one of the most fascinating and important structures in nature. So far, histology has been the gold standard for imaging anatomical features on the sub-cellular level. Using standard optical microscopy, spatial resolution is restricted to a fraction of a micron. Reciprocal space techniques, including small-angle X-ray scattering (SAXS), with an inverse relation between a nanostructure’s size and scattering angle, have been used to study animal and human tissues. The myelin sheaths responsible for insulating axons, for example, exhibit a periodicity between 15 and 18 nm. In order to localize their abundance and orientation, we have performed SAXS measurements with a micrometer-sized beam along a slice of human brain and related them to the histology of myelin-stained tissue. The experimental results elucidate that, compared to histology, micrometer-resolved SAXS provides information about the orientation of myelin, and consequently axons, in addition to myelin abundance. The acquired data show color-coded orientation maps of the nanostructures, thereby providing a detailed insight into the nanoanatomy of a relevant part of the human brain.

A combination of measurements of crystal truncation roda and X-ray standing waves has been used for a detailed characterization of buried Ge δ layers on Si(001). Measurements of crystal truncation rods reveal the interface roughness, the δ layer lattice constant and the δ layer concentration. From measurements with X-ray standing waves the dopant lattice position and crystallinity of the δ layer are determined. We find a linear dependence of the local tetragonal distortion of the Ge bonding in the δ layer on the Ge concentration in the layer.

Using variothermal polymer micro-injection molding, disposable arrays of eight polymer micro-cantilevers each 500 μm long, 100 μm wide and 25 μm thick were fabricated. The present study took advantage of an easy flow grade polypropylene. After gold coating for optical read-out and asymmetrical sensitization, the arrays were introduced into the Cantisens(®) Research system to perform mechanical and functional testing. We demonstrate that polypropylene cantilevers can be used as biosensors for medical purposes in the same manner as the established silicon ones to detect single-stranded DNA sequences and metal ions in real-time. A differential signal of 7 nm was detected for the hybridization of 1 μM complementary DNA sequences. For 100 nM copper ions the differential signal was found to be (36 ± 5) nm. Nano-mechanical sensing of medically relevant, nanometer-size species is essential for fast and efficient diagnosis.