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Allergic reactions occurring after tattooing, especially after the use of red tattoo ink ingredients are relatively rare. We report a painful skin reaction occurring 6 months after the tattoing of the right lower extremity in a 30-year-old female patient. Pathohistological and immunchemical results confirmed a pseudolymphoma. Only the tangential excision of the affected areas led to a sufficient healing process. Split thickness skin grafts were used for defect coverage. 2 years later, the patient was still pain free and the wounds had healed completely without any irritation.

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim We investigate the N = 9 atoms wide armchair-type graphene nanoribbons (9-AGNRs) by performing a comprehensive spectroscopic and microscopic characterization of this novel material. In particular, we use X-ray photoelectron, near edge X-ray absorption fine structure, scanning tunneling, polarized Raman and angle-resolved photoemission (ARPES) spectroscopies. The ARPES measurements are aided by calculations of the photoemission matrix elements which yield the position in k space having the strongest photoemission cross section. Comparison with well-studied narrow N = 7 AGNRs shows that the effective electron mass in 9-AGNRs is reduced by two times and the valence band maximum is shifted to lower binding energy by ∼0.6 eV. In polarized Raman measurements of the aligned 9-AGNR, we reveal anisotropic signal depending upon the phonon symmetry. Our results indicate the 9-AGNRs are a novel 1D semiconductor with a high potential in nanoelectronic applications.

We demonstrate the alignment-preserving transfer of parallel graphene nanoribbons (GNRs) onto insulating substrates. The photophysics of such samples is characterized by polarized Raman and photoluminescence (PL) spectroscopies. The Raman scattered light and the PL are polarized along the GNR axis. The Raman cross section as a function of excitation energy has distinct excitonic peaks associated with transitions between the one-dimensional parabolic subbands. We find that the PL of GNRs is intrinsically low but can be strongly enhanced by blue laser irradiation in ambient conditions or hydrogenation in ultrahigh vacuum. These functionalization routes cause the formation of sp3 defects in GNRs. We demonstrate the laser writing of luminescent patterns in GNR films for maskless lithography by the controlled generation of defects. Our findings set the stage for further exploration of the optical properties of GNRs on insulating substrates and in device geometries.

One-dimensional (1D) graphene nanoribbons (GNRs) are promising materials for future electronics and optoelectronics. Their versatility in electronic properties makes it possible to use them as an active element in devices with a tunable band gap. Different from graphene, armchair-edge GNRs (AGNRs) are semiconducting with a direct bandgap [1-3]. However, until now their photophysical characterization has not been addressed properly due to the metal substrate on which they are grown. The substrate hinders measurements such as transmission and photoluminescence (PL). Here we transfer AGNRs with a width of N = 7 atoms from Au(788) to insulating substrates using an alignment-preserving method and investigate their photoluminescence properties.

A semiconductor-to-metal transition in N = 7 armchair graphene nanoribbons causes drastic changes in its electron and phonon system. By using angle-resolved photoemission spectroscopy of lithium-doped graphene nanoribbons, a quasiparticle band gap renormalization from 2.4 to 2.1 eV is observed. Reaching high doping levels (0.05 electrons per atom), it is found that the effective mass of the conduction band carriers increases to a value equal to the free electron mass. This giant increase in the effective mass by doping is a means to enhance the density of states at the Fermi level which can have palpable impact on the transport and optical properties. Electron doping also reduces the Raman intensity by one order of magnitude, and results in relatively small (4 cm−1) hardening of the G phonon and softening of the D phonon. This suggests the importance of both lattice expansion and dynamic effects. The present work highlights that doping of a semiconducting 1D system is strikingly different from its 2D or 3D counterparts and introduces doped graphene nanoribbons as a new tunable quantum material with high potential for basic research and applications.

© 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim A semiconductor-to-metal transition in N = 7 armchair graphene nanoribbons causes drastic changes in its electron and phonon system. By using angle-resolved photoemission spectroscopy of lithium-doped graphene nanoribbons, a quasiparticle band gap renormalization from 2.4 to 2.1 eV is observed. Reaching high doping levels (0.05 electrons per atom), it is found that the effective mass of the conduction band carriers increases to a value equal to the free electron mass. This giant increase in the effective mass by doping is a means to enhance the density of states at the Fermi level which can have palpable impact on the transport and optical properties. Electron doping also reduces the Raman intensity by one order of magnitude, and results in relatively small (4 cm−1) hardening of the G phonon and softening of the D phonon. This suggests the importance of both lattice expansion and dynamic effects. The present work highlights that doping of a semiconducting 1D system is strikingly different from its 2D or 3D counterparts and introduces doped graphene nanoribbons as a new tunable quantum material with high potential for basic research and applications.

© 2017 American Chemical Society. We demonstrate the alignment-preserving transfer of parallel graphene nanoribbons (GNRs) onto insulating substrates. The photophysics of such samples is characterized by polarized Raman and photoluminescence (PL) spectroscopies. The Raman scattered light and the PL are polarized along the GNR axis. The Raman cross section as a function of excitation energy has distinct excitonic peaks associated with transitions between the one-dimensional parabolic subbands. We find that the PL of GNRs is intrinsically low but can be strongly enhanced by blue laser irradiation in ambient conditions or hydrogenation in ultrahigh vacuum. These functionalization routes cause the formation of sp3 defects in GNRs. We demonstrate the laser writing of luminescent patterns in GNR films for maskless lithography by the controlled generation of defects. Our findings set the stage for further exploration of the optical properties of GNRs on insulating substrates and in device geometries.

In recent years, solid-state spin systems have emerged as promising candidates for quantum information processing (QIP). Prominent examples are the Nitrogen-Vacancy (NV) center in diamond, phosphorous dopants in silicon (Si:P), rare-earth ions in solids and V$_{\text{Si}}$-centers in Silicon-carbide (SiC). The Si:P system has demonstrated, that by eliminating the electron spin of the dopant, its nuclear spins can yield exceedingly long spin coherence times. For NV centers, however, a proper charge state for storage of nuclear spin qubit coherence has not been identified yet. Here, we identify and characterize the positively charged NV center as an electron-spin-less and optically inactive state by utilizing the nuclear spin qubit as a probe. We control the electronic charge and spin utilizing nanometer scale gate electrodes. We achieve a lengthening of the nuclear spin coherence times by a factor of 20. Surprisingly, the new charge state allows switching the optical response of single nodes facilitating full individual addressability., 8 pages, 4 figures, 1 table

We report a systematic ab-initio density functional theory investigation of Ni(111) surface alloyed with elements of group IV (Si, Ge and Sn), demonstrating the possibility to use it to grow high quality graphene. Ni(111) surface represents an ideal substrate for graphene, due to its catalytic properties and perfect matching with the graphene lattice constant. However, Dirac bands of graphene growth on Ni(111) are completely destroyed due to the strong hybridization between carbon pz and Ni d orbitals. Group IV atoms, namely Si, Ge and Sn, once deposited on Ni(111) surface, form an ordered alloyed surface with √ 3 × √ 3-R30◦ reconstruction. We demonstrate that, at variance with the pure Ni(111) surface, alloyed surfaces effectively decouple graphene from the substrate, resulting unstrained due to the nearly perfect lattice matching and preserves linear Dirac bands without the strong hybridization with Ni d states. The proposed surfaces can be prepared before graphene growth without resorting on post-growth processes which necessarily alter the electronic and structural properties of graphene.

In this work, we present a model of the surface states of nonsymmorphic semimetals. These are derived from surface mass terms that lift the high degeneracy imposed in the band structure by the nonsymmorphic bulk symmetries. Reflecting the reduced symmetry at the surface, the bulk bands are strongly modified. This leads to the creation of two-dimensional floating bands, which are distinct from Shockley states, quantum well states or topologically protected surface states. We focus on the layered semimetal ZrSiS to clarify the origin of its surface states. We demonstrate an excellent agreement between DFT calculations and ARPES measurements and present an effective four-band model in which similar surface bands appear. Finally, we emphasize the role of the surface chemical potential by comparing the surface density of states in samples with and without potassium coating. Our findings can be extended to related compounds and generalized to other crystals with nonsymmorphic symmetries., Comment: 8 pages, 5 figures

A semiconductor-to-metal transition in N = 7 armchair graphene nanoribbons causes drastic changes in its electron and phonon system. By using angle-resolved photoemission spectroscopy of lithium-doped graphene nanoribbons, a quasiparticle band gap renormalization from 2.4 to 2.1 eV is observed. Reaching high doping levels (0.05 electrons per atom), it is found that the effective mass of the conduction band carriers increases to a value equal to the free electron mass. This giant increase in the effective mass by doping is a means to enhance the density of states at the Fermi level which can have palpable impact on the transport and optical properties. Electron doping also reduces the Raman intensity by one order of magnitude, and results in relatively small (4 cm−1) hardening of the G phonon and softening of the D phonon. This suggests the importance of both lattice expansion and dynamic effects. The present work highlights that doping of a semiconducting 1D system is strikingly different from its 2D or 3D counterparts and introduces doped graphene nanoribbons as a new tunable quantum material with high potential for basic research and applications.

Der Calcium-sensing receptor (CaSR) ist ein G-Protein gekoppelter Rezeptor und ist primär in der Nebenschilddrüse exprimiert. Die Hauptaufgabe des Rezeptors ist die Regulierung des Calciumhaushalts. Weiters ist dieser jedoch auch in unterschiedliche physiologische als auch pathophysiologische Bedingungen wie Hormonsekretion, Proliferation und Differenzierung involviert. Ziel dieser Masterarbeit ist es das CASR Gen in Zelllinien des Colorectalcarcinoms genetisch zu charakterisieren und eine stabil transfizierte Zelllinie mit einer CaSR Überexpression zu erstellen. Die Hypothese hierfür ist, dass der CaSR ein Tumorsuppressor ist und Überexpression des CaSR in transfizierten Zellen zu verminderter Proliferation und erhöhter Differenzierung als auch Apoptose führt. Mittels DNA Sequenzierung wurden sieben colorectale Zelllinien auf Mutationen im CASR Gen überprüft und detektierte Varianten anhand der Datenbank Alamut® Visual analysiert, um Informationen über die möglichen Auswirkungen der Varianten auf die Aktivität des CaSR zu erhalten. Die Transfektion wurde mit zwei unterschiedlichen Plasmiden (cDNA3.1/kan(+)-FLAG-CaSR-EGFP und cDNA3.1/kan(+)-FLAG-EGFP) an den Zelllinien HT-29 und SW-480 mittels LipofectamineTM LTX 3000 durchgeführt. Zur weiterführenden Untersuchung der transfizierten Zellen wurde der MAPK Phosphorylation Antibody Array durchgeführt. Zehn Genvarianten wurden detektiert, davon sieben Polymoprhismen und drei Mutationen. Drei dieser Polymorphismen führen zu Missense-Substitutionen im codierenden Bereich und vier Polymorphismen liegen im nicht-codierenden Bereich des Gens. Mutationen wurden nur in der Zelllinie DLD-1 gefunden. Dabei geht die Anzahl der Mutationen mit der Passagennummer einher. Die stabile als auch die transiente Transfektion der Zelllinie HT-29 waren nicht erfolgreich. So wurde alternativ die Zelllinie SW-480 transient transfiziert Der MAPK Phsophorylation Antibody Array an transfizierten SW-480 Zellen zeigte eine geringe Auswirkung der Behandlung mit Kalzium Um die Bedeutung von Mutationen des CASR Gens in colorectalem Karzinom zu verstehen, sind noch weitere Untersuchungen notwendig. Als weiterführendes Experiment ist eine stabile Transfektion an der Zelllinie SW-480 inklusive in vitro und in vivo Experimenten geplant. The calcium sensing receptor (CaSR) is a G protein-coupled receptor and is mainly expressed in the parathyroid gland. Its central role is the regulation of calcium homeostasis but it also regulates other processes, as hormone secretion, proliferation, differentiation. In cancer it can act either as an oncogene or as a tumour suppressor depending on the tissue. The aim of this master thesis is to genetically characterise the CASR in CRC cell lines and to establish a stable transfected CRC cell line overexpressing CaSR. The hypothesis is that the CaSR is an oncogene and its overexpression leads to decreased proliferation and increased differentiation and apoptosis, by regulating phosphorylation of signalling molecules in the transfected cells. We analysed seven CRC cell lines by DNA sequencing using specific primers for the CASR. Detected CASR variants were analysed with the mutation software Alamut® Visual and compared to the literature to obtain information about the potential effect of the variant on the activity of the CaSR. The transfection was performed on HT-29 and SW-480 cells using LipofectamineTM LTX 3000 and two different plasmids: cDNA3.1/kan(+)-FLAG-CaSR-EGFP and cDNA3.1/kan(+)-FLAG-EGFP. As a functional assay the MAPK Phosphorylation Antibody Array was performed. Ten variants were detected: seven polymorphisms and three mutations. Three polymorphisms cause missense substitutions in the coding region and four polymorphisms were in the non-coding region of the gene. The variants leading to mutant proteins were found only in the DLD-1 cell line. Stable as well as transient transfection of HT-29 cells did not work. Alternatively SW-480 cells were transiently transfected. The MAPK Phosphorylation Antibody Array showed only a minor effect of the treatment with calcium. To understand the significance of CaSR mutants in colorectal tumorigenesis further investigations are needed. As a future experiment a stable transfection on SW-480 cells as well as in vitro and afterwards in vivo studies with those will be performed. vorgelegt von: Rebecca Maria Grüneis Wien, FH Campus Wien, Masterarb., 2017

Many propositions have been already put forth for the practical use of N-graphene in various devices, such as batteries, sensors, ultracapacitors, and next generation electronics. However, the chemistry of nitrogen imperfections in this material still remains an enigma. Here we demonstrate a method to handle N-impurities in graphene, which allows efficient conversion of pyridinic N to graphitic N and therefore precise tuning of the charge carrier concentration. By applying photoemission spectroscopy and density functional calculations, we show that the electron doping effect of graphitic N is strongly suppressed by pyridinic N. As the latter is converted into the graphitic configuration, the efficiency of doping rises up to half of electron charge per N atom.

A setup for the preparation of oriented Au(111)/mica thin films of ∼100 nm thickness as an active substrate for graphene nanoribbon growth is shown. Low-energy electron diffraction shows that the Au(111) thin films have a single crystallographic orientation over the whole surface area. Graphene nanoribbons are synthesized by the bottom-up approach via surface polymerization of precursor molecules that are evaporated onto the catalytically active Au(111)/mica substrate. The graphene nanoribbons are investigated by a combination of resonance Raman, X-ray photoemission spectroscopy, and near-edge X-ray absorption fine structure spectroscopy confirming a nanoribbon quality equal to nanoribbons grown on commercially available single-crystal Au(111) substrates. The present work, therefore, establishes the insitu preparation of Au(111)/mica as an inexpensive and simple method to prepare substrates of desired shape and thickness for surface polymerization reactions which are of interest to a growing community of researchers working on graphene nanoribbons.

We study the decomposition of the Coulomb integrals of periodic systems into a tensor contraction of six matrices of which only two are distinct. We find that the Coulomb integrals can be well approximated in this form already with small matrices compared to the number of real space grid points. The cost of computing the matrices scales as O(N^4) using a regularized form of the alternating least squares algorithm. The studied factorization of the Coulomb integrals can be exploited to reduce the scaling of the computational cost of expensive tensor contractions appearing in the amplitude equations of coupled cluster methods with respect to system size. We apply the developed methodologies to calculate the adsorption energy of a single water molecule on a hexagonal boron nitride monolayer in a plane wave basis set and periodic boundary conditions.

Our scientific view on climate change adaptation (CCA) is unsatisfying in many ways: It is often dominated by a modernistic perspective of planned pro-active adaptation, with a selective focus on measures directly responding to climate change impacts and thus it is far from real-life conditions of those who are actually affected by climate change. Farmers have to simultaneously adapt to multiple changes. Therefore, also empirical climate change adaptation research needs a more integrative perspective on real-life climate change adaptations. This also has to consider “hidden” adaptations, which are not explicitly and directly motivated by CCA but actually contribute to the sector’s adaptability to climate change. The aim of the present study is to develop and test an analytic framework that contributes to a broader understanding of CCA and to bridge the gap between scientific expertise and practical action. The framework distinguishes three types of CCA according to their climate related motivations: explicit adaptations, multi-purpose adaptations, and hidden adaptations. Although agriculture is among the sectors that are most affected by climate change, results from the case study of Tyrolean mountain agriculture show that climate change is ranked behind other more pressing “real-life-challenges” such as changing agricultural policies or market conditions. We identified numerous hidden adaptations which make a valuable contribution when dealing with climate change impacts. We conclude that these hidden adaptations have not only to be considered to get an integrative und more realistic view on CCA; they also provide a great opportunity for linking adaptation strategies to farmers’ realities.