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-Lα,ß 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.

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.

Evaluation of treatment response to enzyme replacement therapy with Velaglucerase alfa in patients with Gaucher disease using whole-body magnetic resonance imaging.

OBJECTIVE: This was a retrospective data analysis to evaluate the treatment response to enzyme replacement therapy (ERT) with Velaglucerase alfa using whole-body magnetic resonance imaging (MRI). MATERIALS AND METHODS: A baseline and follow-up MRI were performed on 18 Gaucher Type 1 patients at an interval of 11.6 months. The MRI score systems determined the Bone-Marrow-Burden (BMB) score, the Düsseldorf-Gaucher score (DGS), and the Vertebra-Disc-Ratio (VDR). The Severity Score Index Type 1 (GD-DS3) was also assessed. RESULTS: The baseline MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.70; while, the follow-up MRI medians were: BMB, 7.00; DGS, 3.00; and VDR: 1.73. The baseline GD-DS3 median was 2.40 (BMB excl.: 0.50) and the follow-up median was 2.00 (BMB excl.: 0.50). There was weak statistical significance with the Wilcoxon signed-rank test for the DGS (p=0.034) and GD-DS3 (p=0.047) between both MRIs. CONCLUSION: Velaglucerase alfa therapy is a effective long-term treatment for Gaucher Type 1 patients who are newly diagnosed or switching therapies. Measurements with whole-body MRI and an objective scoring system were reliable tools for detecting early stage bone marrow activity. Further research is needed to evaluate the "Booster-Effect" of Velaglucerase alfa therapy in Gaucher skeletal disease.

[Preclinical and clinical management after mass disaster : Experiences from the train collision in Bad Aibling on 9 February 2016]. / Präklinisches und klinisches Management nach Massenunfall : Erfahrungen aus dem Zugunglück Bad Aibling am 9.2.2016.

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.

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.

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.

Antioxidant amelioration of dilated cardiomyopathy caused by conditional deletion of NEMO/IKKgamma in cardiomyocytes.

RATIONALE: Insight into the function of nuclear factor (NF)-kappaB in the adult heart has been hampered by the embryonic lethality of constitutive NF-kappaB inactivation. OBJECTIVE: The goal of the present study was therefore to gain insights into the role of NF-kappaB pathway specifically in mouse cardiomyocytes by conditional deletion of the NF-kappaB 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.

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.

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.

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.

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.

Microwave emission from superconducting vortices in Mo/Si superlattices.

Most of superconductors in a magnetic field are penetrated by a lattice of quantized flux vortices. In the presence of a transport current causing the vortices to cross sample edges, emission of electromagnetic waves is expected due to the continuity of tangential components of the fields at the surface. Yet, such a radiation has not been observed so far due to low radiated power levels and lacking coherence in the vortex motion. Here, we clearly evidence the emission of electromagnetic waves from vortices crossing the layers of a superconductor/insulator Mo/Si superlattice. The emission spectra consist of narrow harmonically related peaks which can be finely tuned in the GHz range by the dc bias current and, coarsely, by the in-plane magnetic field value. Our findings show that superconductor/insulator superlattices can act as dc-tunable microwave generators bridging the frequency gap between conventional radiofrequency oscillators and (sub-)terahertz generators relying upon the Josephson effect.

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.

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.

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.