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Purpose To develop a self-gating method capable of assessing nonuniform motion, e.g., in cardiovascular magnetic resonance imaging of patients with severe arrhythmia, or for imaging of the temporomandibular joint. Methods The proposed method allows cyclic motion trajectories with a nonuniform pace by replacing the one-dimensional gating signal of conventional image-based self-gating with a two-dimensional gating matrix. The resulting image quality is compared with conventional self-gating and real-time MRI. Results Nonuniform self-gating resulted in superior image quality compared with conventional self-gating and the feasibility study showed significantly improved image sharpness (P

Purpose The combination of fully balanced SSFP sequences with iterative golden angle radial sparse parallel (iGRASP) MRI leads to strong image artifacts due to eddy currents caused by the large angular increment of the golden angle ordering. The purpose of this work is to enable the combination of iterative golden angle radial sparse parallel MRI with balanced SSFP using the recently presented tiny golden angles. Methods The tiny golden angle trajectories are analyzed for their incoherence properties in relation to sparse imaging using the time-resolved point-spread functions. Tiny golden angle radial sparse parallel (tyGRASP) MRI is introduced and evaluated with applications in cardiac imaging and dynamic imaging of the temporomandibular joint. The results are analyzed in detail for 3 T and verified for 1.5 T. Results The incoherence properties of the tiny golden angle trajectory are comparable to the incoherence properties of the golden angle trajectory and are well suited for sparse MRI reconstruction. The proposed tiny golden angle radial sparse parallel MRI method strongly reduces eddy current related artifacts for both applications. Conclusion This work enables sparse, golden-ratio-based imaging with balanced SSFP sequences. Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.

Purpose: The polychromatic nature of the x-ray beams and their effects on the reconstructed image are often disregarded during standard image reconstruction. This leads to cupping and beam hardening artifacts inside the reconstructed volume. To correct for a general cupping, methods like water precorrection exist. They correct the hardening of the spectrum during the penetration of the measured object only for the major tissue class. In contrast, more complex artifacts like streaks between dense objects need other techniques of correction. If using only the information of one single energy scan, there are two types of corrections. The first one is a physical approach. Thereby, artifacts can be reproduced and corrected within the original reconstruction by using assumptions in a polychromatic forward projector. These assumptions could be the used spectrum, the detector response, the physical attenuation and scatter properties of the intersected materials. A second method is an empirical approach, which does not rely on much prior knowledge. This so-called empirical beam hardening correction (EBHC) and the previously mentioned physical-based technique are both relying on a segmentation of the present tissues inside the patient. The difficulty thereby is that beam hardening by itself, scatter, and other effects, which diminish the image quality also disturb the correct tissue classification and thereby reduce the accuracy of the two known classes of correction techniques. The herein proposed method works similar to the empirical beam hardening correction but does not require a tissue segmentation and therefore shows improvements on image data, which are highly degraded by noise and artifacts. Furthermore, the new algorithm is designed in a way that no additional calibration or parameter fitting is needed. Methods: To overcome the segmentation of tissues, the authors propose a histogram deformation of their primary reconstructed CT image. This step is essential for the proposed algorithm to be segmentation-free (sf). This deformation leads to a nonlinear accentuation of higher CT-values. The original volume and the gray value deformed volume are monochromatically forward projected. The two projection sets are then monomially combined and reconstructed to generate sets of basis volumes which are used for correction. This is done by maximization of the image flatness due to adding additionally a weighted sum of these basis images. sfEBHC is evaluated on polychromatic simulations, phantom measurements, and patient data. The raw data sets were acquired by a dual source spiral CT scanner, a digital volume tomograph, and a dual source micro CT. Different phantom and patient data were used to illustrate the performance and wide range of usability of sfEBHC across different scanning scenarios. The artifact correction capabilities are compared to EBHC. Results: All investigated cases show equal or improved image quality compared to the standard EBHC approach. The artifact correction is capable of correcting beam hardening artifacts for different scan parameters and scan scenarios. Conclusions: sfEBHC generates beam hardening-reduced images and is furthermore capable of dealing with images which are affected by high noise and strong artifacts. The algorithm can be used to recover structures which are hardly visible inside the beam hardening-affected regions.

The genus Lactobacillus includes over 215 species that colonize plants, foods, sewage and the gastrointestinal tract (GIT) of humans and animals. In the GIT, Lactobacillus population can be made by true inhabitants or by bacteria occasionally ingested with fermented or spoiled foods, or with probiotics. This study longitudinally surveyed Lactobacillus species and strains in the feces of a healthy subject through whole genome sequencing (WGS) data-mining, in order to identify members of the permanent or transient populations. In three time-points (0, 670 and 700 d), 58 different species were identified, 16 of them being retrieved for the first time in human feces. L. rhamnosus, L. ruminis, L. delbrueckii, L. plantarum, L. casei and L. acidophilus were the most represented, with estimated amounts ranging between 6 and 8 Log (cells g(-1)), while the other were detected at 4 or 5 Log (cells g(-1)). 86 Lactobacillus strains belonging to 52 species were identified. 43 seemingly occupied the GIT as true residents, since were detected in a time span of almost 2 years in all the three samples or in 2 samples separated by 670 or 700 d. As a whole, a stable community of lactobacilli was disclosed, with wide and understudied biodiversity.

The objective of this study was to investigate the potential of ultra short echo time imaging for the assessment of caries lesions and early demineralization. 12 patients with suspected caries lesions underwent a dental magnetic resonance imaging investigation comprising ultra short echo time imaging (echo time=50 μs) and spin echo imaging. Before the dental magnetic resonance imaging, all patients underwent a conventional clinical dental investigation including visual assessment of the teeth as well as dental x-ray imaging. All lesions identifiable in the x-ray could be clearly identified in the ultra short echo time images, but only about 19% of the lesions were visible in the spin echo images. In 19% of all lesions, the lesions could be more clearly delineated in the ultra short echo time images than in the x-ray images. This was especially the case for secondary lesions. In direct comparison with the x-ray images, all lesions appeared substantially larger in the dental magnetic resonance imaging data. The presented data provide evidence that caries lesions can be identified in ultra short echo time magnetic resonance imaging with high sensitivity. The apparent larger volume of the lesions in dental magnetic resonance imaging may be attributed to fluid accumulation in demineralized areas without substantial breakdown of mineral structures.

GaAs crystals have been grown without B2O3 encapsulation by the vapour-pressure controlled Czochralski (VCz) method to reduce undesired boron incorporation and to enable in situ control of the Ga/As ratio in the melt. With increasing Ga content of the melt the omnipresent As precipitate concentration decreases in as-grown GaAs crystals. Semiinsulating (SI) GaAs crystals could been obtained even from melts with a composition of 46 at.% As. Comparative cathodoluminescence (CL) measurements on those crystals and on boron-contaminated GaAs show that the luminescence bands at 1.316 eV and at 1.441 eV are related to BAs. Reduced concentrations of boron and EL2 result in significant lower near-band edge absorption, mainly caused by the photoionization cross section of As antisites in SI GaAs. These VCz GaAs crystals possess improved optical properties. Semi-conducting (SC) GaAs:Si crystals were grown from near-stoichiometric melts. Positron annihilation lifetime spectroscopy measurements show that the low boron concentration in our SC VCz GaAs results always in 3 times higher Ga vacancy concentrations compared to standard SC GaAs. CL bands due to optical transitions at 0.95 eV and 1.15 eV are related to auto-compensating (VGaSiGa)2- and (SiGaVGaSiGa)– complexes, respectively, and depend on the doping level. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

In LEC-grown oxygen-containing GaAs, a vibrational absorption line is observed at 2059.6 cm–1 for T = 7 K after long-time annealing at (700 ± 100) °C. This line is due to the stretching mode of a 12C–16O complex, since the line due to the isotopically shifted 13C–16O mode is observed at 2003.8 cm–1. Several other 12C–16O stretching modes found in this frequency region are assigned to C–O complexes with different environments. The formation of C–O complexes around 700 °C becomes possible as a result of the mobility of oxygen atoms. After the same annealing procedure, two vibrational lines are measured at 1828.2 and 1891.4 cm–1 for T = 7 K and assigned to the stretching modes of an 11B–16O (10B–16O) complex. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Different kinds of bread, stored at constant temperature and at controlled humidity conditions for a week since their manufacturing date, were analysed by Attenuated Total Reflectance-Fourier Transform InfraRed (ATR-FTIR) spectroscopy. The collected spectra were processed by Principal Component Analysis (PCA), in order to evaluate the changes occurring during bread ageing. For the sake of comparison, the 1060-950 cm−1-1 spectral window has been also investigated by curve-fitting methods. It was observed that the first PC increases monotonically with ageing of samples. Furthermore, the more influential variables on PC1 correspond to spectral regions where are located stretching and bending bands, which are mainly attributed to typical starch bonds vibrations.

In LEC-grown InP, about 30 sharp vibrational absorption lines are measured in the frequency region 2200 to 2350 cm–1. All these lines are due to phosphorus-hydrogen stretching modes. Experiments on InP containing both hydrogen and deuterium finally proved that the line at 2202.4 cm–1 is due to a single hydrogen atom bonded to P in an indium vacancy (VIn) and that the line at 2315.6 cm–1 is due to the complex of four P–H bonds in an VIn. In InP:H:D, this VInH4 complex gives rise to six vibrational lines in the region of P–H modes and six lines in the region of P–D modes because of the five different types of VInHnDm complexes. The measured frequencies of these 12 lines are in excellent agreement with those obtained from ab initio calculations reported in the literature. Additional P–H complexes are discussed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The local vibrational mode absorption lines at 3079.2 and 983.3 cm−1, measured in semi-insulating LEC-grown GaAs, are due to the stretching and wagging mode of one hydrogen bonded to a light impurity atom. The investigation of GaAs grown without boric oxide encapsulant delivers arguments that this impurity atom is nitrogen in the nitrogen-vacancy (NAs–VGa) defect, which is responsible for the vibrational quadruplet line at 638 cm−1. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

In LEC-grown GaP doped with silicon, two vibrational absorption lines are measured at 2175.1 and 2190.3 cm -1 (T= 7 K). These lines are due to P-H stretching modes where hydrogen passivates Si Ga donors. Uniaxial stress experiments show that the P-H-Si Ga complex responsible for the 2175.1 cm -1 line has trigonal symmetry and is the isolated passivated Si Ga . The complex creating the 2190.3 cm -1 line has the symmetry C s and contains additionally a B Ga with the four constituents located in an {110} mirror plane. Therefore, also the structure of the group-IV donor-hydrogen complexes is in GaP different from that observed in GaAs.

In LEC-grown GaAs and GaP with an oxygen content larger than 10 15 cm -3 , two sharp vibrational absorption lines are investigated located at 3108.0 as well as 3235.0 cm -1 for GaAs and 3106.0 as well as 3250.9 cm -1 for GaP. These lines are due to the stretching modes of hydrogen bonded to interstitial oxygen in two different centres (O i -H) I and (O i -H) II as proved by the detection of the isotopically shifted lines in material doped additionally with deuterium. Centre (O i -H) I is a single hydrogen atom bonded to oxygen and is in GaAs photosensitive at temperatures lower than 100 K. (O i -H) II is a di-hydrogen centre with the two hydrogen atoms being on equivalent positions around O.

The electrical properties of p-type GaP: Cr: Zn and n-type GaP: Cr: S samples have been studied using Deep Level Transient Spectroscopy (DLTS). In GaP:Cr:Zn a deep hole emitting level is detected with a thermal activation energy of E v + 0.48 eV and attributed to the Cr 3+/4+ donor level of substitutional Cr Ga . In GaP: Cr: S a deep electron emitting level is detected at E c - 0.30 eV and attributed to the Cr +/2+ double acceptor level of Cr Ga . The emission rates of both levels are found to be electric field dependent which can be fitted by a Poole-Frenkel model. Deep Level Optical Spectroscopy (DLOS) measurements were performed on both levels in the filled as well as in their emptied state. The Frank-Condon shifts were estimated from these measurements. The spectral shape of these DLOS spectra is discussed as due to photoionization transitions.

In liquid encapsulated Czochralski (LEC) grown GaP, a set of twelve vibrational absorption lines is measured in the frequency region 500 to 1150 cm -1 . They originate from a single defect as their intensities are correlated with each other. It is shown that this defect is a [N-O] complex consisting of several nitrogen and oxygen atoms. This complex is characteristic of GaP produced with the LEC technique under high nitrogen inert gas pressure conditions.

In the past it has been demonstrated that the carbon concentration of large semi-insulating (SI) GaAs single crystals grown by the conventional liquid encapsulation Czochralski (LEC) technique can be controlled by several methods including variations of growth parameters. It was the aim of the present paper to clarify which of the relationships of LEC growth could be used for a carbon control in the VCz-method characterized by the application of an inner chamber made from graphite to avoid selective As evaporation. In detail this comprised a study of the influence of several growth parameters like the water content of the boric oxide, the composition of the working atmosphere, the gas flow, a titanium gettering and additions of gallium oxide. As a result, for the first time carbon concentrations down to ≈ 1014 cm-3 were obtained in 3'' (75 mm) diameter VCz crystals.

EPR experiments on titanium-doped n- and p-type GaP are reported. In n-type GaP:Ti co-doped with sulphur additional to the known isolated defects an angular dependent spectrum showing trigonal symmetry can be observed. The analysis suggests that the spectrum is caused by a donor-acceptor nearest-neighbour pair defect [Ti-Sp]. Theparameters of the spin-Hamiltonian are determined as follows: S = l, g | = g⟂ = 1.95(1), |D| = 0.0670(5) cm−1. The concentration of thepair defect confirms that Coulomb attraction is responsible for its preferential formation. However, no EPR spectrum of a pair can be proved for p-type GaP: Ti co-doped with Zn, although the existence of such a pair is also most probable. The lack of the EPR spectrum could have spectroscopical reasons. An Titan-dotiertem n- und p-GaP werden EPR-Experimente durchgefuhrt. Zusatzlich zu den bekannten EPR-Spektren der isolierten Defekte im n-GaP:Ti: S wird ein winkelabhangiges Spektrum beobachtet. Das Spektrum zeigt trigonale Symmetrie. Aus der Spektrenanalyse folgt, das das Spektrum durchein [Ti2Ga+-Sp] Donator-Akzeptor-Paar hervorgerufen wird, wobei die Paarionen nachste Nachbarn sind. Folgende Parameter des Spin-Hamilton-Operators wurden bestimmt: S = 1, g | = g⟂ = 1.95(1), |D| = 0.0670(5)cm−1. Die Konzentration der Paare bestatigt, das sich das Paar aufgrund der Coulombkraft bevorzugt bildet. Kein EPR-Paarspektrum kann dagegen in p-GaP: Ti: Zn nachgewiesen werden, obwohl die Existenz eines Ti-Zn Paares ebenfalls sehr wahrscheinlich ist. Das Fehlen eines EPR-Spektrums konnte spektroskopische Ursachen haben.

Six types of family-of-origin frames-coping, modeling, role, definition, reversal, and loyalty frames-are utilized in understanding three common couple interactional situations: pursuing/distancing, overfunctioning/underfunctioning, and blaming/placating. Clinical examples are used to illustrate the process of constructing family-of-origin frames in couples therapy.

Scanning electron microscope investigations of cathodoluminescence (CL) are used to demonstrate the electrical homogeneity improvement of semi-insulating LEC GaAs by post growth annealing. Annealing conditions are varied in a broad temperature and time scale in order to find optimum annealing parameters (lowest possible temperature and annealing time) for sufficient homogenization. An objective characterization of the degree of homogenization achieved is obtained by investigating CL profiles aross dislocation cell structures. Changes occuring in the crystals during annealing are discussed basing on CL profile measurements and CL micrographs, respectively. An attempt is made to explain homogenization in terms of surface processes as well as bulk mechanisms. [Russian Text Ignored].