Transcranial direct current stimulation (tDCS) is a non-invasive technique to modulate human brain responses and has been used successfully in the treatment of depression. In this study tDCS was used as an add-on to psychotherapeutic interventions for the treatment of nicotine dependence. The goal of this study is to investigate modifications of brain activity before and after tDCS therapy.

The study is based on a sample of 32 smokers, 22 to 65 years; participants were divided into a placebo group and a verum group. Each participated in fMRI measurements before and after treatment (tDCS plus psychotherapy). During the fMRI sessions, pictures with or without a connection to smoking were presented in a pseudo-randomised order, in order to assess craving-related responses.

The results indicate cue-related brain activations, mainly within the basal ganglia, in the thalamus, the occipital cortex and the cuneus. The verum group showed an increased activation of the frontal cortex which is possibly related to a reinforcement of the brain's control function. The placebo group demonstrated reduced responses in the thalamus, the parahippocampal gyrus and the occipital cerebral cortex after tDCS, which may be related to changes of general attention and alertness.

Tobacco dependence is one of the most common preventable risk factors for health damage. The consequences of this addiction are not only shown on various organ systems, but also lead to changes on neuronal level.

The aim of the investigation was to detect neural responses in the reward system in smokers versus nonsmokers. For that purpose, the processing of reward – associated stimuli under withdrawal is compared to the neural activity after nicotine – consumption.

40 volunteers (20 smokers, 20 nonsmokers), between 18 and 60 years, were enrolled in the study. The smokers were further devided into two groups. One group was first measured in deprivation, secondly after smoking, the second group in inverse order. After a resting sequence in a 3T MRI, the participants took part in a gambling paradigm with real financial profit and loss.

The preliminary results show differences in reward-related neural structures like amygdala, hippocampus between smokers and nonsmokers. In addition, differences were found among smokers depending on the current smoking status (withdrawal or tobacco consumption).

Reward related structures are differentially activated, depending on active consumption versus withdrawal. Thus these data furthermore point out the importance of smoking status in neurobiological and treatment studies.

Tobacco dependence can lead to a variety of different symptoms. One important aspect of tobacco dependence is the strong desire to consume the substance (craving). Craving is controlled by multiple cognitive, emotional and motivational processes. Previous studies have shown that craving can be increased during the visual perception of smoking-related cues. The aim of this study was to examine the influence of the nicotine status on craving-related responses.

Functional MRI (3 Tesla) was used to detect brain responses during the presentation of neutral and tobacco-associated pictures. Smokers were scanned twice, deprived of tobacco as well as non-deprived, in alternating order.

So far, the results show a significantly increased neural activity during the presentation of tobacco-related cues in smokers compared to healthy controls, especially in the secondary visual cortex as well as parts of the frontal lobe and the hippocampus. At the time of tobacco withdrawal, smokers demonstrated increased neural responses during the presentation of tobacco-related pictures, especially in emotion-related areas of the brain.

The results indicate that the visual impression of smoking-related cues can lead to a different neuronal activity in patients with tobacco addiction, especially during deprivation. We would like to suggest that the increased allocation of attention and enhanced emotional responses should be considered in therapeutic approaches.

The present work shows results on elemental distribution analyses in Cu(In,Ga)Se2 thin films for solar cells performed by use of wavelength-dispersive and energy-dispersive X-ray spectrometry (EDX) in a scanning electron microscope, EDX in a transmission electron microscope, X-ray photoelectron, angle-dependent soft X-ray emission, secondary ion-mass (SIMS), time-of-flight SIMS, sputtered neutral mass, glow-discharge optical emission and glow-discharge mass, Auger electron, and Rutherford backscattering spectrometry, by use of scanning Auger electron microscopy, Raman depth profiling, and Raman mapping, as well as by use of elastic recoil detection analysis, grazing-incidence X-ray and electron backscatter diffraction, and grazing-incidence X-ray fluorescence analysis. The Cu(In,Ga)Se2 thin films used for the present comparison were produced during the same identical deposition run and exhibit thicknesses of about 2 μm. The analysis techniques were compared with respect to their spatial and depth resolutions, measuring speeds, availabilities, and detection limits.

An integral involving a combination of Legendre polynomials, exponential and algebraic terms is solved using the generating function. Special cases of this result are compared with known expansions, and the previously known results are shown to be extendible to a particularly pleasing result as a limiting case. Comparisons provide some new combinatorial identities involving binomials. Finally, an effective numerical procedure is described which evaluates the integral to machine accuracy.

Ultrahard boron nitride compacts containing nanosized domains of the cubic (c-BN), wurtzitic (w-BN), and hexagonal (h-BN) phase were synthesized at high-pressure/high-temperature (HP/HT) conditions. Hot-pressed and pyrolytic BN, both containing h-BN as a main component, were used as starting materials. The HP/HT products were investigated by x-ray diffraction via Rietveld and line-profile analysis, as well as high-resolution transmission electron microscopy. c-BN was the dominant phase in all products, complemented by up to 25 wt% w-BN and some remaining “compressed h-BN.” In particular samples, partial crystallographic coherence of adjacent crystallites to x-rays was observed, which has been previously found in superhard transition metal nitride-based nanocomposite coatings. In the BN nanocomposites, the partial coherence of nanocrystallites to x-rays was improved by their strong local preferred orientation, which is made possible by the well-known orientation relationships among h-BN, w-BN, and c-BN phases. The correlation between the weight fraction and the average size of the c-BN crystallites helped to describe the formation of c-BN/(w-BN) nanocomposites from submicron-sized h-BN domains in the starting materials. The Knoop and Vickers hardness of specimens with crystallite sizes ranging from 6 to ∼50 nm was found to be significantly higher than that of c-BN single crystals, despite the presence of residual h-BN.

Based on computer-generated templates, percolation objects were fabricated. Random-site, semi-continuous swiss cheese, and semi-continuous inverse swiss-cheese percolation models above the percolation threshold were considered. The water-filled pore space was investigated by nuclear magnetic resonance (NMR) imaging and in the presence of a pressure gradient, by NMR velocity mapping. The percolation backbones were determined using velocity maps. The fractal dimension of the backbones turned out to be smaller by about 17 % than that of the complete cluster. As a further relation of interest, the volume-averaged velocity was calculated as a function of the probe volume radius. In a certain scaling window, the resulting dependence can be represented by a power law. The experimental results favorably compare to computer simulations with the finite-element method (FEM) or the finite-volume method (FVM). Thermal convection in percolation clusters of different porosities was studied using the NMR velocity mapping technique. The velocity distribution is related to the convection roll size distribution. The maximum velocity as a function of the porosity clearly visualizes a closed-loop percolation transition if the Rayleigh number conditions are appropriate. Percolation theory suggests a relationship between the anomalous diffusion exponent and the fractal dimension of the cluster, i.e. between a dynamic and a structural parameter. Interdiffusion between two compartments initially filled with H2O and D2O, respectively, was examined by proton imaging. The results confirm the theoretical expectation. Finally, advection driven dispersive transport was investigated in the large Péclet number limit. The superdiffusive transport anomaly was demonstrated and discussed in terms of the non-local advection-diffusion and the fractional diffusion theories.

Hafnium nitride films were deposited by ion-beam sputtering, and characterized for their composition, electrical, structural, mechanical and optical characteristics. Films were found to vary widely in their properties, based upon the parameters under which they were deposited. The films were found to have a nitrogen to hafnium ratio of up to 1.45:1, resistivity varying from 10−2 to 105 Ω-cm, as well as widely variable optical characteristics, depending on process variables. Structural characterization of the dielectric phase HfNx (x>l) material by X-ray and electron diffraction reveals a distortion of the hafnium mononitride rock salt structure with increasing amounts of nitrogen, in accordance with previous findings. Infrared spectroscopic characterization of the thin film dielectric phase hafnium nitride optical properties reveals the likely existence of multiple bonding between nitrogen in the material.

Contour scaling is often observed on building facades, especially built from clay-rich sandstones. The paper shows that a soluble salt enriched zone and a decrease of the flexural strength below the stone surface can be detected even if a damage is not yet visible. A computer simulated wetting-drying process demonstrates that the mean humidity maximum is situated below the surface. Its depth coincides with the depth of the salt maximum and strenth minimum.