Simultaneous Dimensional and Analytical Characterization of Ordered Nanostructures

The spatial and compositional complexity of 3D structures employed in today's nanotechnologies has developed to a level at which the requirements for process development and control can no longer fully be met by existing metrology techniques. For instance, buried parts in stratified nanostructures, which are often crucial for device functionality, can only be probed in a destructive manner in few locations as many existing nondestructive techniques only probe the objects surfaces. Here, it is demonstrated that grazing exit X-ray fluorescence can simultaneously characterize an ensemble of regularly ordered nanostructures simultaneously with respect to their dimensional properties and their elemental composition. This technique is nondestructive and compatible to typically sized test fields, allowing the same array of structures to be studied by other techniques. For crucial parameters, the technique provides sub-nm discrimination capabilities and it does not require access-limited large-scale research facilities as it is compatible to laboratory-scale instrumentation.

Sizes of pure and doped helium droplets from single shot x-ray imaging

Advancements in x-ray free-electron lasers on producing ultrashort, ultrabright, and coherent x-ray pulses enable single-shot imaging of fragile nanostructures, such as superfluid helium droplets. This imaging technique gives unique access to the sizes and shapes of individual droplets. In the past, such droplet characteristics have only been indirectly inferred by ensemble averaging techniques. Here, we report on the size distributions of both pure and doped droplets collected from single-shot x-ray imaging and produced from the free-jet expansion of helium through a 5 μm diameter nozzle at 20 bars and nozzle temperatures ranging from 4.2 to 9 K. This work extends the measurement of large helium nanodroplets containing 10⁹-10¹¹ atoms, which are shown to follow an exponential size distribution. Additionally, we demonstrate that the size distributions of the doped droplets follow those of the pure droplets at the same stagnation condition but with smaller average sizes.

Ultra-fast vortex motion in a direct-write Nb-C superconductor

The ultra-fast dynamics of superconducting vortices harbors rich physics generic to nonequilibrium collective systems. The phenomenon of flux-flow instability (FFI), however, prevents its exploration and sets practical limits for the use of vortices in various applications. To suppress the FFI, a superconductor should exhibit a rarely achieved combination of properties: weak volume pinning, close-to-depairing critical current, and fast heat removal from heated electrons. Here, we demonstrate experimentally ultra-fast vortex motion at velocities of 10-15 km s-1 in a directly written Nb-C superconductor with a close-to-perfect edge barrier. The spatial evolution of the FFI is described using the edge-controlled FFI model, implying a chain of FFI nucleation points along the sample edge and their development into self-organized Josephson-like junctions (vortex rivers). In addition, our results offer insights into the applicability of widely used FFI models and suggest Nb-C to be a good candidate material for fast single-photon detectors.

How to Recognize Animals' Vulnerability: Questioning the Orthodoxies of Moral Individualism and Relationalism in Animal Ethics

Simple Summary

Many animal ethicists consider cognitive capacities as being the basis for the moral status of an animal. On this view, animals that have, for instance, complex experiences, future preferences, or at least the ability to suffer, impose an obligation on us. Those beings that do not share these capacities do not have a moral status. This would also apply to embryos, infants, or severely cognitively impaired humans, but this seems to be at odds with many of our shared ethical intuitions. As a response, so-called relationalists argue that our different relations to different kinds of beings form the basis for moral obligations. However, on this view, it remains unclear (a) why it is particularly our relations to kinds of animals that are morally relevant; and (b) how we can criticize and change these relations. This paper seeks to combine both accounts of animal ethics to overcome these pitfalls. It argues that it is individual vulnerability that forms the basis of moral obligations, but that social structures and relations pre-determine how we perceive and recognize vulnerability. However, particular relationships with animals as well as open possibilities to treat animals in different ways (e.g., to treat a dairy cow not as a mere resource) render critique and change of current practices possible.

Abstract

This paper presents vulnerability and the social structures surrounding recognition of vulnerability as fundamental elements of animal ethics. Theories in the paradigm of moral individualism often treat individual rational capacities as the basis of moral considerability. However, this implies that individuals without such capacities (such as human or nonhuman infants) are excluded even though we grant them special protection in our lived morality. It also means that moral agents are pictured as disembodied, impartial observers, independent of social relations and particular relationships. Relationalists take moral obligations to be rooted in different kinds of beings. However, relationalism runs the risk of losing the individual animal and her capacities. It cannot also it adequately explain what forms different kinds of being, or the constitution of normativity through relations. Moreover, it lacks resources to explain how critique and change are possible. This paper argues that vulnerability and its recognition are the source of our moral obligations to animals. It seeks to combine individualist and relationalist arguments by using a social ontology of the bodily individual which can be applied to human agents and to any vulnerable being. Social structures predetermine the ways in which we perceive and recognize the vulnerability of living beings. However, we are not fully determined by these structures; particular relationships and direct encounters with individual animals as well as the open possibilities of treating animals differently that are immanent in common practices render critique and change of current conditions possible.

Alloy multilayers and ternary nanostructures by direct-write approach

The fabrication of nanopatterned multilayers, as used in optical and magnetic applications, is usually achieved by two independent steps, which consist in the preparation of multilayer films and in the successive patterning by means of lithography and etching processes. Here we show that multilayer nanostructures can be fabricated by using focused electron beam induced deposition (FEBID), which allows the direct writing of nanostructures of any desired shape with nanoscale resolution. In particular, [Formula: see text] multilayers are prepared by the alternating deposition from the metal carbonyl precursors, [Formula: see text] and [Formula: see text], and neopentasilane, [Formula: see text]. The ability to fabricate nanopatterned multilayers by FEBID is of interest for the realization of hyperbolic metamaterials and related nanodevices. In a second experiment, we treated the multilayers by low-energy electron irradiation in order to induce atomic species intermixing with the purpose to obtain ternary nanostructured compounds. Transmission electron microscopy and electrical transport measurements indicate that in thick multilayers, (n = 12), the intermixing is only partial, taking place mainly in the upper part of the structures. However, for thin multilayers, (n = 2), the intermixing is such that a transformation into the L2₁ phase of the Co₂FeSi Heusler compound takes place over the whole sample volume.

An easy-to-build, low-budget point-of-care ultrasound simulator: from Linux to a web-based solution

BACKGROUND

Hands-on training in point-of-care ultrasound (POC-US) should ideally comprise bedside teaching, as well as simulated clinical scenarios. High-fidelity phantoms and portable ultrasound simulation systems are commercially available, however, at considerable costs. This limits their suitability for medical schools. A Linux-based software for Emergency Department Ultrasound Simulation (edus2TM) was developed by Kulyk and Olszynski in 2011. Its feasibility for POC-US education has been well-documented, and shows good acceptance. An important limitation to an even more widespread use of edus2, however, may be due to the need for a virtual machine for WINDOWS^® systems. Our aim was to adapt the original software toward an HTML-based solution, thus making it affordable and applicable in any simulation setting.

METHODS

We created an HTML browser-based ultrasound simulation application, which reads the input of different sensors, triggering an ultrasound video to be displayed on a respective device. RFID tags, NFC tags, and QR Codes™ have been integrated into training phantoms or were attached to standardized patients. The RFID antenna was hidden in a mock ultrasound probe. The application is independent from the respective device.

RESULTS

Our application was used successfully with different trigger/scanner combinations and mounted readily into simulated training scenarios. The application runs independently from operating systems or electronic devices.

CONCLUSION

This low-cost, browser-based ultrasound simulator is easy-to-build, very adaptive, and independent from operating systems. It has the potential to facilitate POC-US training throughout the world, especially in resource-limited areas.

Laboratory Setup for Scanning-Free Grazing Emission X-ray Fluorescence

Grazing incidence and grazing emission X-ray fluorescence spectroscopy (GI/GE-XRF) are techniques that enable nondestructive, quantitative analysis of elemental depth profiles with a resolution in the nanometer regime. A laboratory setup for soft X-ray GEXRF measurements is presented. Reasonable measurement times could be achieved by combining a highly brilliant laser produced plasma (LPP) source with a scanning-free GEXRF setup, providing a large solid angle of detection. The detector, a pnCCD, was operated in a single photon counting mode in order to utilize its energy dispersive properties. GEXRF profiles of the Ni-L_α,β line of a nickel-carbon multilayer sample, which displays a lateral (bi)layer thickness gradient, were recorded at several positions. Simulations of theoretical profiles predicted a prominent intensity minimum at grazing emission angles between 5° and 12°, depending strongly on the bilayer thickness of the sample. This information was used to retrieve the bilayer thickness gradient. The results are in good agreement with values obtained by X-ray reflectometry, conventional X-ray fluorescence and transmission electron microscopy measurements and serve as proof-of-principle for the realized GEXRF setup. The presented work demonstrates the potential of nanometer resolved elemental depth profiling in the soft X-ray range with a laboratory source, opening, for example, the possibility of in-line or even in situ process control in semiconductor industry.

Simultaneous atomic-resolution electron ptychography and Z-contrast imaging of light and heavy elements in complex nanostructures

The aberration-corrected scanning transmission electron microscope (STEM) has emerged as a key tool for atomic resolution characterization of materials, allowing the use of imaging modes such as Z-contrast and spectroscopic mapping. The STEM has not been regarded as optimal for the phase-contrast imaging necessary for efficient imaging of light materials. Here, recent developments in fast electron detectors and data processing capability is shown to enable electron ptychography, to extend the capability of the STEM by allowing quantitative phase images to be formed simultaneously with incoherent signals. We demonstrate this capability as a practical tool for imaging complex structures containing light and heavy elements, and use it to solve the structure of a beam-sensitive carbon nanostructure. The contrast of the phase image contrast is maximized through the post-acquisition correction of lens aberrations. The compensation of defocus aberrations is also used for the measurement of three-dimensional sample information through post-acquisition optical sectioning.

Simultaneous atomic-resolution electron ptychography and Z-contrast imaging of light and heavy elements in complex nanostructures

The aberration-corrected scanning transmission electron microscope (STEM) has emerged as a key tool for atomic resolution characterization of materials, allowing the use of imaging modes such as Z-contrast and spectroscopic mapping. The STEM has not been regarded as optimal for the phase-contrast imaging necessary for efficient imaging of light materials. Here, recent developments in fast electron detectors and data processing capability is shown to enable electron ptychography, to extend the capability of the STEM by allowing quantitative phase images to be formed simultaneously with incoherent signals. We demonstrate this capability as a practical tool for imaging complex structures containing light and heavy elements, and use it to solve the structure of a beam-sensitive carbon nanostructure. The contrast of the phase image contrast is maximized through the post-acquisition correction of lens aberrations. The compensation of defocus aberrations is also used for the measurement of three-dimensional sample information through post-acquisition optical sectioning.

The use of ptychography with electrons has been limited. Here, Yang et al. demonstrate that the combination of Z-contrast and phase imaging reveals the structure of complex nanomaterials. This practical tool can be used to solve the structure of a beam-sensitive carbon nanostructure at atomic-resolution.

dc and ac magnetic properties of thin-walled Nb cylinders with and without a row of antidots

dc and ac magnetic properties of two thin-walled superconducting Nb cylinders with a rectangular cross-section are reported. Magnetization curves and the ac response were studied on as-prepared and patterned samples in magnetic fields parallel to the cylinder axis. A row of micron-sized antidots (holes) was made in the film along the cylinder axis. Avalanche-like jumps of the magnetization are observed for both samples at low temperatures for magnetic fields not only above H c1, but in fields lower than H c1 in the vortex-free region. The positions of the jumps are not reproducible and they change from one experiment to another, resembling vortex lattice instabilities usually observed for magnetic fields larger than H c1. At temperatures above [Formula: see text] and [Formula: see text] the magnetization curves become smooth for the patterned and the as-prepared samples, respectively. The magnetization curve of a reference planar Nb film in the parallel field geometry does not exhibit jumps in the entire range of accessible temperatures. The ac response was measured in constant and swept dc magnetic field modes. Experiment shows that ac losses at low magnetic fields in a swept field mode are smaller for the patterned sample. For both samples the shapes of the field dependences of losses and the amplitude of the third harmonic are the same in constant and swept field near H c3. This similarity does not exist at low fields in a swept mode.

A liquid jet setup for x-ray scattering experiments on complex liquids at free-electron laser sources

In this paper we describe a setup for x-ray scattering experiments on complex fluids using a liquid jet. The setup supports Small and Wide Angle X-ray Scattering (SAXS/WAXS) geometries. The jet is formed by a gas-dynamic virtual nozzle (GDVN) allowing for diameters ranging between 1 μm and 20 μm at a jet length of several hundred μm. To control jet properties such as jet length, diameter, or flow rate, the instrument is equipped with several diagnostic tools. Three microscopes are installed to quantify jet dimensions and stability in situ. The setup has been used at several beamlines performing both SAXS and WAXS experiments. As a typical example we show an experiment on a colloidal dispersion in a liquid jet at the X-ray Correlation Spectroscopy instrument at the Linac Coherent Light Source free-electron laser.

[Preclinical and clinical management after mass disaster : Experiences from the train collision in Bad Aibling on 9 February 2016]

Mass casualty incidents (MCI) in this day and age represent a special challenge, which initially require on-site coordination and logistics and then a professional distribution of victims (triage) to surrounding hospitals. Technical, logistical and even specialist errors can impair this flow of events. It therefore seems advisable to make a detailed analysis of every MCI. In this article the railway incident from 9 February 2016 is analyzed taking the preclinical and clinical cirumstances into consideration and conclusions for future management are drawn. As a special entity it could be determined that fixed table units in passenger trains represent a particularly dangerous hazard and in many instances in this analysis led to characteristic abdominal and thoracic injuries.

Application of a pnCCD for energy-dispersive Laue diffraction with ultra-hard X-rays

In this work the spectroscopic performance of a pnCCD detector in the ultra-hard energy range between 40 and 140 keV is tested by means of an energy-dispersive Laue diffraction experiment on a GaAs crystal. About 100 Bragg peaks were collected in a single-shot exposure of the arbitrarily oriented sample to white synchrotron radiation provided by a wiggler at BESSY II and resolved in a large reciprocal-space volume. The positions and energies of individual Laue spots could be determined with a spatial accuracy of less than one pixel and a relative energy resolution better than 1%. In this way the unit-cell parameters of GaAs were extracted with an accuracy of 0.5%, allowing for a complete indexing of the recorded Laue pattern. Despite the low quantum efficiency of the pnCCD (below 7%), experimental structure factors could be obtained from the three-dimensional data sets, taking into account photoelectric absorption as well as Compton scattering processes inside the detector. The agreement between measured and theoretical kinematical structure factors calculated from the known crystal structure is of the order of 10%. The results of this experiment demonstrate the potential of pnCCD detectors for applications in X-ray structure analysis using the complete energy spectrum of synchrotron radiation.

Radiation dose reduction in postoperative computed position control of cochlear implant electrodes in lambs - An experimental study

OBJECTIVE

Cochlear implants (CI) are standard treatment for prelingually deafened children and postlingually deafened adults. Computed tomography (CT) is the standard method for postoperative imaging of the electrode position. CT scans accurately reflect electrode depth and position, which is essential prior to use. However, routine CT examinations expose patients to radiation, which is especially problematic in children. We examined whether new CT protocols could reduce radiation doses while preserving diagnostic accuracy.

METHODS

To investigate whether electrode position can be assessed by low-dose CT protocols, a cadaveric lamb model was used because the inner ear morphology is similar to humans. The scans were performed at various volumetric CT dose-indexes CTDIvol)/kV combinations. For each constant CTDIvol the tube voltage was varied (i.e., 80, 100, 120 and 140kV). This procedure was repeated at different CTDIvol values (21mGy, 11mGy, 5.5mGy, 2.8mGy and 1.8mGy). To keep the CTDIvol constant at different tube voltages, the tube current values were adjusted. Independent evaluations of the images were performed by two experienced and blinded neuroradiologists. The criteria diagnostic usefulness, image quality and artifacts (scaled 1-4) were assessed in 14 cochlear-implanted cadaveric lamb heads with variable tube voltages.

RESULTS

Results showed that the standard CT dose could be substantially reduced without sacrificing diagnostic accuracy of electrode position. The assessment of the CI electrode position was feasible in almost all cases up to a CTDIvol of 2-3mGy. The number of artifacts did not increase for images within this dose range as compared to higher dosages. The extent of the artifacts caused by the implanted metal-containing CI electrode does not depend on the radiation dose and is not perceptibly influenced by changes in the tube voltage. Summarizing the evaluation of the CI electrode position is possible even at a very low radiation dose.

CONCLUSIONS

CT imaging of the temporal bone for postoperative electrode position control of the CI is possible with a very low and significantly radiation dose. The tube current-time product and voltage can be reduced by 50% without increasing artifacts. Low-dose postoperative CT scans are sufficient for localizing the CI electrode.

Patient position and hypoxemia during propofol sedation for colonoscopy: a randomized trial

AIM

To evaluate the benefits of the left lateral position in avoiding hypoxemic events in patients undergoing colonoscopy.

METHODS

We conducted a randomized, prospective, controlled trial at two study sites in Germany. Patients undergoing colonoscopy under propofol sedation were randomized to either the supine or left lateral position. The primary outcome was oxygen desaturation (SaO2<90%). Secondary outcome measures were apneic events, hypotension, patient satisfaction, propofol dosage, cecal intubation time, and adenoma detection.

RESULTS

A total of 412 patients were randomized 1:1 to undergo colonoscopy in the supine or left lateral position. No severe adverse events were observed in either group. Intention-to-treat analysis revealed no significant difference in the frequency of desaturation in the left lateral arm compared with the supine arm (6.8% vs. 12.1%; P=0.064). Patients in the left lateral arm showed lower apnea rates (9.4% vs. 16.2%; P= .040), but had more episodes of hypotension (12.3% vs. 2.9%; P<0.001). The frequency of repositioning was higher in the left lateral group. No significant differences were observed in patient satisfaction and cooperation, propofol dosage, or adenoma detection rate. Patients who were repositioned to facilitate endoscope passage were excluded from per-protocol analysis. The incidence of hypoxemia was lower for the left lateral than for the supine group in per-protocol analysis (1.8% vs. 11.2%; P=0.003).

CONCLUSION

The positioning of patients in the left lateral position during propofol sedation for colonoscopy results in lower desaturation rates provided the position can be maintained throughout endoscopy. ClinicalTrials.gov NCT02001792.

Direct writing of CoFe alloy nanostructures by focused electron beam induced deposition from a heteronuclear precursor

Recently, focused electron beam-induced deposition has been employed to prepare functional magnetic nanostructures with potential in nanomagnetic logic and sensing applications by using homonuclear precursor gases like Fe(CO)5 or Co2(CO)8. Here we show that an extension towards the fabrication of bi-metallic compounds is possible by using a single-source heteronuclear precursor gas. We have grown CoFe alloy magnetic nanostructures from the HFeCo3(CO)12 metal carbonyl precursor. The compositional analysis indicates that the samples contain about 80 at% of metal and 10 at% of carbon and oxygen. Four-probe magnetotransport measurements are carried out on nanowires of various sizes down to a width of 50 nm, for which a room temperature resistivity of 43 μΩcm is found. Micro-Hall magnetometry reveals that 50 nm × 250 nm nanobars of the material are ferromagnetic up to the highest measured temperature of 250 K. Finally, the transmission electron microscopy (TEM) microstructural investigation shows that the deposits consist of a bcc Co-Fe phase mixed with a FeCo2 O4 spinel oxide phase with nanograins of about 5 nm diameter.

Post-growth purification of Co nanostructures prepared by focused electron beam induced deposition

In the majority of cases nanostructures prepared by focused electron beam induced deposition (FEBID) employing an organometallic precursor contain predominantly carbon-based ligand dissociation products. This is unfortunate with regard to using this high-resolution direct-write approach for the preparation of nanostructures for various fields, such as mesoscopic physics, micromagnetism, electronic correlations, spin-dependent transport and numerous applications. Here we present an in situ cleaning approach to obtain pure Co-FEBID nanostructures. The purification procedure lies in the exposure of heated samples to a H2 atmosphere in conjunction with the irradiation by low-energy electrons. The key finding is that the combination of annealing at 300 °C, H2 exposure and electron irradiation leads to compact, carbon- and oxygen free Co layers down to a thickness of about 20 nm starting from as-deposited Co-FEBID structures. In addition to this, in temperature-dependent electrical resistance measurements on post-processed samples we find a typical metallic behavior. In low-temperature magnetoresistance and Hall effect measurements we observe ferromagnetic behavior.

[Life-threatening bleeding in obsessive-compulsive disorder]

We report on a case of life-threatening hemorrhoidal bleeding due to obsessive-compulsive disorder. The patient had irrational fears and felt compelled to defecate at least 3 times a day. This required massive abdominal pressing and caused inguinal hernias and prolapsed hemorrhoids. Severe obsessive-compulsive rituals may often result in physical complications. Conversely, obsessive-compulsive disorder should be considered when patients present with uncommon physical complaints, particularly skin symptoms or abnormalities in the context of micturition and defecation.

Magnetoresistance of granular Pt-C nanostructures close to the metal-insulator transition

We investigate the electrical and magneto-transport properties of Pt-C granular metals prepared by focused electron beam induced deposition. In particular, we consider samples close to the metal-insulator transition obtained from as-grown deposits by means of a low-energy electron irradiation treatment. The temperature dependence of the conductivity shows a σ ∼lnT behavior, with a transition to σ ∼ √T at low temperature, as expected for systems in the strong coupling tunneling regime. The magnetoresistance is positive and is described within the wavefunction shrinkage model, normally used for disordered systems in the weak coupling regime. In order to fit the experimental data, spin-dependent tunneling has to be taken into account. In the discussion we attribute the origin of the spin-dependency to the confinement effects of Pt nano-grains embedded in the carbon matrix.

Synthesis of nanowires via helium and neon focused ion beam induced deposition with the gas field ion microscope

The ion beam induced nanoscale synthesis of platinum nanowires using the trimethyl (methylcyclopentadienyl)platinum(IV) (MeCpPt(IV)Me3) precursor is investigated using helium and neon ion beams in the gas field ion microscope. The He(+) beam induced deposition resembles material deposited by electron beam induced deposition with very small platinum nanocrystallites suspended in a carbonaceous matrix. The He(+) deposited material composition was estimated to be 16% Pt in a matrix of amorphous carbon with a large room-temperature resistivity (∼3.5 × 10(4)-2.2 × 10(5) μΩ cm) and temperature-dependent transport behavior consistent with a granular material in the weak intergrain tunnel coupling regime. The Ne(+) deposited material has comparable composition (17%), however a much lower room-temperature resistivity (∼600-3.0 × 10(3) μΩ cm) and temperature-dependent electrical behavior representative of strong intergrain coupling. The Ne(+) deposited nanostructure has larger platinum nanoparticles and is rationalized via Monte Carlo ion-solid simulations which show that the neon energy density deposited during growth is much larger due to the smaller ion range and is dominated by nuclear stopping relative to helium which has a larger range and is dominated by electronic stopping.

Anomalous signal from S atoms in protein crystallographic data from an X-ray free-electron laser

X-ray free-electron lasers (FELs) enable crystallographic data collection using extremely bright femtosecond pulses from microscopic crystals beyond the limitations of conventional radiation damage. This diffraction-before-destruction approach requires a new crystal for each FEL shot and, since the crystals cannot be rotated during the X-ray pulse, data collection requires averaging over many different crystals and a Monte Carlo integration of the diffraction intensities, making the accurate determination of structure factors challenging. To investigate whether sufficient accuracy can be attained for the measurement of anomalous signal, a large data set was collected from lysozyme microcrystals at the newly established `multi-purpose spectroscopy/imaging instrument' of the SPring-8 Ångstrom Compact Free-Electron Laser (SACLA) at RIKEN Harima. Anomalous difference density maps calculated from these data demonstrate that serial femtosecond crystallography using a free-electron laser is sufficiently accurate to measure even the very weak anomalous signal of naturally occurring S atoms in a protein at a photon energy of 7.3 keV.

Rumination, gender, and depressive symptoms associated with caregiving strain in bipolar disorder

OBJECTIVE

To evaluate the associations between indices of caregiving strain, ruminative style, depressive symptoms, and gender among family members of patients with bipolar disorder.

METHOD

One hundred and fifty primary caregivers of patients enrolled in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) participated in a cross-sectional study to evaluate the role of ruminative style in maintaining depressive symptoms associated with caregiving strain. Patient lifetime diagnosis and current episode status were evaluated by the Affective Disorder Evaluation and the Clinical Monitoring Form. Caregivers were evaluated within 30 days of the patient on measures of family strain, depressive symptoms, and ruminative style.

RESULTS

Men and women did not differ on depression, caregiver strain, or ruminative style scores. Scores suggest an overall mild level of depression and moderate caregiver strain for the sample. Greater caregiver strain was significantly associated (P<0.05) with rumination and level of depressive symptoms, controlling for patient clinical status and demographic variables. Rumination reduced the apparent association between strain and depression by nearly half. Gender was not significantly associated with depression or rumination.

CONCLUSION

Rumination helps explain depressive symptoms experienced by both male and female caregivers of patients with bipolar disorder. Interventions for caregivers targeted at decreasing rumination should be considered.

Room temperature L1₀ phase transformation in binary CoPt nanostructures prepared by focused-electron-beam-induced deposition

CoPt-C binary alloys have been fabricated by focused-electron-beam-induced deposition by the simultaneous use of Co₂(CO)₈ and (CH₃)₃CH₃C₅H₄Pt as precursor gases. The alloys are made of CoPt nanoparticles embedded in a carbonaceous matrix. TEM investigations show that as-grown samples are in an amorphous phase. By means of a room temperature low-energy electron irradiation treatment the CoPt nanoparticles transform into face-centered tetragonal L1₀ nanocrystallites. In parallel, the system undergoes a transition from a superparamagnetic to a ferromagnetic state at room temperature. By variation of the post-growth irradiation dose the electrical and magneto-transport properties of the alloy can be continuously tuned.

Neural Stem Cell Spreading on Lipid Based Artificial Cell Surfaces, Characterized by Combined X-ray and Neutron Reflectometry

We developed a bioadhesive coating based on a synthetic peptide-conjugate (AK-cyclo[RGDfC]) which contains multiples of the arginyl-glycyl-aspartic acid (RGD) amino acid sequence. Biotinylated AK-cyclo[RGDfC] is bound to a supported lipid bilayer via a streptavidin interlayer. Layering, hydration and packing of the coating is quantified by X-ray and neutron reflectometry experiments. AK-cyclo[RGDfC] binds to the streptavidin interlayer in a stretched-out on edge configuration. The highly packed configuration with only 12% water content maximizes the number of accessible adhesion sites. Enhanced cell spreading of neural stem cells was observed for AK-cyclo[RGDfC] functionalized bilayers. Due to the large variety of surfaces which can be coated by physisorption of lipid bilayers, this approach is of general interest for the fabrication of biocompatible surfaces.

Pentacene thin-film transistors encapsulated by a thin alkane layer operated in an aqueous ionic environment

The encapsulation of pentacene thin-film transistors (TFTs) by a 50 nm thick layer of a long chain alkane (C₄₄H₉₀) enables the operation in an aqueous solution of 1 mM NaCl. It is the first time that pentacene TFTs operate successfully in a liquid environment. This opens new perspectives for biocompatible sensor devices based on pentacene TFTs.

Artificial granularity in two-dimensional arrays of nanodots fabricated by focused-electron-beam-induced deposition

We have prepared 2D arrays of nanodots embedded in an insulating matrix by means of focused-electron-beam-induced deposition using the W(CO)(6) precursor. By varying the deposition parameters, i.e. the electron beam current and energy and the raster constant, we obtain an artificial granular material with tunable electrical properties. The analysis of the temperature dependence of the conductivity and of the current-voltage characteristic suggests that the transport mechanism is governed by electron tunneling between artificial grains. In order to understand the nature of the granularity and thus the microstructural origin of the electronic transport behavior, we perform TEM and micro-Raman investigations. Independent of the deposition parameters, TEM measurements show that the dots are constituted of amorphous tungsten carbide clusters embedded in an amorphous carbonaceous matrix. Micro-Raman spectra show two peaks, around 690 and 860 cm(-1) associated with the W-C stretching modes. Higher frequency peaks give information on the composition of the matrix. In particular, we measure a peak at about 1290 cm(-1), which is associated with sp(3) carbon bonds. Furthermore we detect the so-called D and G peaks, at about 1350 and 1560 cm(-1), associated with the vibration modes of the sp(2) carbon bonds. The analysis of the position of the peaks and of their relative intensity suggests that the composition of the matrix is between nanocrystalline graphite and amorphous carbon.

Antioxidant Amelioration of Dilated Cardiomyopathy Caused by Conditional Deletion of NEMO/IKKγ in Cardiomyocytes

Rationale : Insight into the function of nuclear factor (NF)-κB in the adult heart has been hampered by the embryonic lethality of constitutive NF-κB inactivation.

Objective : The goal of the present study was therefore to gain insights into the role of NF-κB pathway specifically in mouse cardiomyocytes by conditional deletion of the NF-κB essential modulator (NEMO).

Methods and Results : Using a Cre/loxP system, we disrupted the Nemo gene in a cardiomyocyte-specific manner in the heart, which simulated gene expression changes underlying human heart failure and caused adult-onset dilated cardiomyopathy accompanied by inflammation and apoptosis. Pressure overload challenges of NEMO-deficient young hearts precociously induced the functional decrements that develop spontaneously in older knockout animals. Moreover, oxidative stress in NEMO-deficient cardiomyocytes is a critical pathological component that can be attenuated with antioxidant diet in vivo.

Conclusions : These results reveal an essential physiological role for NEMO-mediated signaling in the adult heart to maintain cardiac function in response to age-related or mechanical challenges, in part through modulation of oxidative stress.

The transient electrical conductivity of W-based electron-beam-induced deposits during growth, irradiation and exposure to air

W-based granular metals have been prepared by electron-beam-induced deposition from the tungsten hexacarbonyl W(CO)(6) precursor. In situ electrical conductivity measurements have been performed to monitor the growth process and to investigate the behavior of the deposit under electron beam post-irradiation and by exposure to air. During the first part of the growth process, the electrical conductivity grows nonlinearly, independent of the electron beam parameters. This behavior is interpreted as the result of the increase of the W-particle's diameter. Once the growth process is terminated, the electrical conductivity decreases with the logarithm of time, sigma approximately ln(t). Temperature-dependent conductivity measurements of the deposits reveal that the electrical transport takes place by means of electron tunneling either between W-metal grains or between grains and trap sites in the matrix. After venting the electron microscope the electrical conductivity of the deposits shows a degradation behavior, which depends on the composition. Electron post-irradiation increases the electrical conductivity of the deposits.

Ultrafast exciton relaxation in microcrystalline pentacene films

The exciton dynamics in microcrystalline pentacene films is investigated by transient absorption measurements with 30 fs time resolution. It is found that the emission from photoexcited Frenkel excitons decays within 70 fs due to the ultrafast formation of an excitonic species with a strongly reduced transition dipole to the ground state and an absorption dipole in the plane of the film. We propose that an excimer exciton is formed and stabilized by changes of the local crystal structure. The subsequent dynamics is dominated by diffusion controlled annihilation and trapping.

Does the frontal airbag avoid thoracic injury?

INTRODUCTION

The airbag is an established car safety device. However, recent studies pointed out that even the airbag might cause injuries. Nevertheless, most physicians do consider a lower risk in accident victims sustaining severe injury of the chest, when a deployed frontal airbag has been reported. We set out to verify the frequency and pattern of thoracic injury in car drivers protected by a frontal airbag during traffic accidents.

METHODS

This investigation was conducted as part of a prospective surveillance analyzing traffic accidents. Enrolled were car drivers included in a databank between January 2001 and December 2004 consecutively. The chance for sustaining chest injury with or without a frontal airbag was described using the relative risk.

RESULTS

A total of 188 car drivers were included in the analysis. In 54 (28.7%) cases a deployed airbag and in 134 (71.3%) the absence of an airbag has been documented. Out of those cases 16 (29.6%) drivers with airbag and 30 (22.4%) without airbag sustained a chest injury. The mean abbreviated injury scale (AIS) of chest injuries in drivers with deployed airbag was 2.3 (1-5; SD +/- 1.45; mean injury severity scale [ISS] 21.1 [SD +/- 17.18]), in drivers without airbag 1.6 (1-4; SD +/- 1.12; mean ISS 15.8 [SD +/- 20.6]). For belted drivers with an airbag the relative risk to sustain chest injury was 1.96 compared to those without an airbag.

CONCLUSIONS

The airbag does not avoid chest injury definitively. Much more, it has been demonstrated that the relative risk to sustain relevant thoracic injury seems to be almost higher in restrained drivers with a frontal airbag.

[Inner ear damage due to leisure and broadband noise. An experimental study on initial and permanent functional and morphological damage]

The initial and permanent effects of leisure noise (toy pistols, rock music) compared to broadband noise were examined in 68 guinea pigs. Auditory threshold shifts at 1.5, 2, 3, 4, 6, 8, 12 und 16 kHz were registered before and immediately after exposure as well as on days 1, 2, 3, 5,7 and 21 post-exposure using the auditory brain stem response (ABR) technique. In order to examine cilia and hair cell damage in eight cochlear frequency regions (<0,4 kHz, 0,4-0,8 kHz, 0,8-1.5 kHz, 1.5-3 kHz, 3-5 kHz, 5-11.5 kHz, 11.5-26 kHz und >26 kHz), cytocochleograms were performed immediately after exposure and on days 1, 7 and 21.Frequency dependent functional or morphological damage was found which depended on the type of trauma tested. All results were highly significant ( P<0.001). The results show that partial recovery of hearing occurred within 3 days of acute acoustic trauma induced by toy pistols and within 1 day after exposure to rock music or broadband noise. There was no further recovery of hearing within the following 18 and 20 days, respectively. Furthermore, permanent threshold shifts after exposure to rock music or broadband noise were not associated with cilia and/or hair cell damage.

Nature of heavy quasiparticles in magnetically ordered heavy fermions UPd(2)Al(3) and UPt(3)

The optical conductivity of the heavy fermions UPd(2)Al(3) and UPt(3) has been measured in the energy range from 0.04 to 5 meV. In both compounds a well pronounced pseudogap of less than 1 meV develops in the optical response at low temperatures; we relate this to the antiferromagnetic ordering. From the energy dependence of the effective mass and scattering rate we conclude that the enhancement of the mass mainly occurs below the energy which is related to magnetic correlations between the local magnetic moments and the itinerant electrons. This implies that the magnetic order in these compounds is the prerequisite to the formation of the heavy quasiparticles and eventually to superconductivity.

[Age dependence of laboratory parameters in a health study--attempt at calculating a laboratory index for assessing biological aging]

The laboratory analyses of 404 participants of the health study GUNDULA, 201 men and 203 women between 30 and 80 years old, were performed to evaluate the variables for the determination of biological age. From the more than 70 laboratory variables resulting from clinical-chemical and hematologic tests and from urinalysis, less than 40 are significantly age-dependent. About half of these variables were examined by regression analysis to evaluate whether they are useful for the estimation of biological age by a laboratory index. Considerable sex differences were observed. The laboratory indexes for the participants altogether (resulting from 13 parameters) and separated for women (10 parameters) and men (8 parameters) show more variations than the biological age estimated by non-invasive parameters. In men only, there exists a significant but inverse correlation between laboratory index and relative aging rate, the difference between biological and chronological age. The results of some striking variables (e.g. dehydroepiandrosterone sulfate and others) and the results of an explorative factor analysis with regard to possible interconnections between variables and chronological age will be discussed.

[Clinical laboratory diagnosis and aging. 3: Evaluation of a study of aging--complete blood and urine status]

The results of the determination of hematologic values from 262 men and 242 women, participants of an aging study and half of each group 44.4 +/- 0.9 and 63.0 +/- 0.9 (men) and 44.4 +/- 0.9 and 62.8 +/- 0.8 years old (women), respectively, are compared. In men, one analyte (hemoglobin decreasing) and four indices show significant differences (MCV increasing, MCH decreasing, MCHC decreasing, RDW increasing). In the older group, the iron level and the transferrin saturation are also significantly lower. In women, erythrocytes and the hematocrit are significantly higher in the older group whereas the indices MCH and MCHC are lower and the RDW increases. At the same time, the iron level, transferrin and the transferrin saturation decrease whereas ferritin doubles. The sex differences of the hematologic parameters are more pronounced in the younger participants and especially remarkable in ferritin in both age groups. The results of the semiquantitative analysis of ten urine parameters by reagent strip show differences with respect to sex (e.g., leucocytes and erythrocytes) and age (e.g., specific gravity, pH, nitrite, protein, erythrocytes). The usefulness of the estimation of glucose in urine is discussed in connection with the corresponding serum glucose levels.

Step-edge induced anisotropic domain-wall propagation

We report the observation of anisotropic domain-wall propagation in ultrathin magnetic films with perpendicular anisotropy. A controlled density of step edges was introduced which allowed us to quantify its influence on the domain-wall pinning. For a sawtooth arrangement of the step edges the corresponding wall movement resulted in triangular shaped domains. All aspects of this anisotropic domain-wall evolution could be reproduced by a simulation based on a modified Ginzburg-Landau-type soft-spin model.