Electronic and magnetic structure of epitaxial NiO/Fe3_3O4_4(001) heterostructures grown on MgO(001) and Nb-doped SrTiO3_3(001)

We study the underlying chemical, electronic and magnetic properties of a number of magnetite based thin films. The main focus is placed onto NiO/Fe$_3$O$_4$(001) bilayers grown on MgO(001) and Nb-SrTiO$_3$(001) substrates. We compare the results with those obtained on pure Fe$_3$O$_4$(001) thin films. It is found that the magnetite layers are oxidized and Fe$^{3+}$ dominates at the surfaces due to maghemite ($\gamma$-Fe$_2$O$_3$) formation, which decreases with increasing magnetite layer thickness. From a layer thickness of around 20 nm on the cationic distribution is close to that of stoichiometric Fe$_3$O$_4$. At the interface between NiO and Fe$_3$O$_4$ we find the Ni to be in a divalent valence state, with unambiguous spectral features in the Ni 2p core level x-ray photoelectron spectra typical for NiO. The formation of a significant NiFe$_2$O$_4$ interlayer can be excluded by means of XMCD. Magneto optical Kerr effect measurements reveal significant higher coercive fields compared to magnetite thin films grown on MgO(001), and a 45$^{\circ}$ rotated magnetic easy axis. We discuss the spin magnetic moments of the magnetite layers and find that the moment increases with increasing thin film thickness. At low thickness the NiO/Fe$_3$O$_4$ films grown on Nb-SrTiO$_3$ exhibits a significantly decreased spin magnetic moments. A thickness of 20 nm or above leads to spin magnetic moments close to that of bulk magnetite

Spatiotemporal profile of emission from oscillating dc micro discharges

The axial light distributions in parallel-plate dc microdischarges in argon show similar behavior to large scale discharges. Between the low-current Townsend mode and the high current glow mode exists a large region of currents where different oscillations appear and the dynamic Volt-Ampere characteristic shows hysteresis behavior. During the oscillations the maximum peak intensity moves closer to the cathode, which is characteristic for the abnormal glow regime even though the average current is considerably smaller.Comment: submitted to: IEEE Trans. Plasma Sci., Spec. Issue on Images in Plasma Sc

Axial light emission and Ar metastable densities in a parallel plate dc micro discharge in steady state and transient regimes

Axial emission profiles in a parallel plate dc micro discharge (feedgas: argon; discharge gap d=1mm; pressure p=10Torr) were studied by means of time resolved imaging with a fast ICCD camera. Additionally, volt-ampere (V-A) characteristics were recorded and Ar* metastable densities were measured by tunable diode laser absorption spectroscopy (TDLAS). Axial emission profiles in the steady state regime are similar to corresponding profiles in standard size discharges (d=1cm, p=1Torr). For some discharge conditions relaxation oscillations are present when the micro discharge switches periodically between low current Townsend-like mode and normal glow. At the same time the axial emission profile shows transient behavior, starting with peak distribution at the anode, which gradually moves towards the cathode during the normal glow. The development of argon metastable densities highly correlates with the oscillating discharge current. Gas temperatures in the low current Townsend-like mode (T= 320-400K) and the high current glow mode (T=469-526K) were determined by the broadening of the recorded spectral profiles as a function of the discharge current.Comment: submitted to Plasma Sources Sci. Techno

Evaluation of contraceptive methods in women with congenital heart disease in Germany, Hungary and Japan

Aims For women with congenital heart defects (CHD), pregnancy may pose a health risk. Sexually active women with CHD without the desire for own children or for whom pregnancy would imply considerable health risks require adequate counselling regarding appropriate contraception. This study gathers data on the contraceptive behaviour of women with CHD from three different cultural regions. Methods and results 634 women with CHD from Germany, Hungary and Japan were surveyed regarding contraception and contraceptive methods (CM) used. The patients were divided into groups according to different criteria such as pregnancy associated cardiovascular risk or "safety" of the contraceptive methods used. 59% of the study participants had already gained experience with CM. The average age at the first time of use was 18.4 years; the German patients were significantly younger at the first time of using a CM than those from Hungary and Japan. Overall the condom was the method used the most (38%), followed by oral contraceptives (30%) and coitus interruptus (11%). The range of CM used in Japan was much smaller than that in Germany or Hungary. Unsafe contraceptives were currently, or had previously been used, by 29% of the surveyed patients (Germany: 25%, Hungary: 37%, Japan: 32%). Conclusion Most women with CHD use CM. There are differences between the participating countries. Adequate contraceptive counselling of women with CHD requires considering the individual characteristics of each patient, including potential contraindications. For choosing an appropriate CM, both the methods' "safety", as well as the maternal cardiovascular risk, are important. © 2015 Elsevier Ireland Ltd

A Bayesian method for evaluating and discovering disease loci associations

Background: A genome-wide association study (GWAS) typically involves examining representative SNPs in individuals from some population. A GWAS data set can concern a million SNPs and may soon concern billions. Researchers investigate the association of each SNP individually with a disease, and it is becoming increasingly commonplace to also analyze multi-SNP associations. Techniques for handling so many hypotheses include the Bonferroni correction and recently developed Bayesian methods. These methods can encounter problems. Most importantly, they are not applicable to a complex multi-locus hypothesis which has several competing hypotheses rather than only a null hypothesis. A method that computes the posterior probability of complex hypotheses is a pressing need. Methodology/Findings: We introduce the Bayesian network posterior probability (BNPP) method which addresses the difficulties. The method represents the relationship between a disease and SNPs using a directed acyclic graph (DAG) model, and computes the likelihood of such models using a Bayesian network scoring criterion. The posterior probability of a hypothesis is computed based on the likelihoods of all competing hypotheses. The BNPP can not only be used to evaluate a hypothesis that has previously been discovered or suspected, but also to discover new disease loci associations. The results of experiments using simulated and real data sets are presented. Our results concerning simulated data sets indicate that the BNPP exhibits both better evaluation and discovery performance than does a p-value based method. For the real data sets, previous findings in the literature are confirmed and additional findings are found. Conclusions/Significance: We conclude that the BNPP resolves a pressing problem by providing a way to compute the posterior probability of complex multi-locus hypotheses. A researcher can use the BNPP to determine the expected utility of investigating a hypothesis further. Furthermore, we conclude that the BNPP is a promising method for discovering disease loci associations. © 2011 Jiang et al

Delay in diagnosis of muscle disorders depends on the subspecialty of the initially consulted physician

<p>Abstract</p> <p>Background</p> <p>New therapeutic strategies in muscular dystrophies will make a difference in prognosis only if they are begun early in the course of the disease. Therefore, we investigated factors that influence the time to diagnosis in muscle dystrophy patients.</p> <p>Methods</p> <p>A sample of 101 patients (mean age 49 years; range 19-80; 44% women) with diagnosed muscle dystrophies from neurological practices and the neuromuscular specialty clinic in Berlin, Germany, was invited to participate. Time from first consultation to diagnosis, subspecialty of physician, and sociodemographic data were assessed with self-report questionnaires. The association between time to diagnosis and potential predictors (subspecialty of initially consulted physician, diagnoses, gender, and age at onset) was modeled with linear regression analysis.</p> <p>Results</p> <p>The mean time span between first health-care contact and diagnosis was 4.3 years (median 1). The diagnostic delay was significantly longer if patients were initially seen by a non-neurological specialist compared to a general practitioner (5.2 vs. 3.5 years, p = 0.047). Other factors that were independently associated with diagnostic delay were female gender and inherited muscle disease.</p> <p>Conclusion</p> <p>Action to improve clinical awareness of muscle diseases in non-neurological specialists is needed.</p

Large family with both parents affected by distinct BRCA1 mutations: implications for genetic testing

Although the probability of both parents being affected by BRCA1 mutations is not negligible, such families have not been systematically described in the literature. Here we present a large breast-ovarian cancer family, where 3 sisters and 1 half-sister inherited maternal BRCA1 5382insC mutation while the remaining 2 sisters carried paternal BRCA1 1629delC allele. No BRCA1 homozygous mutations has been detected, that is consistent with the data on lethality of BRCA1 knockout mice. This report exemplifies that the identification of a single cancer-predisposing mutation within the index patient may not be sufficient in some circumstances. Ideally, all family members affected by breast or ovarian tumor disease have to be subjected to the DNA testing, and failure to detect the mutation in any of them calls for the search of the second cancer-associated allele

The role of mechanotransduction versus hypoxia during simulated orthodontic compressive strain—an in vitro study of human periodontal ligament fibroblasts

During orthodontic tooth movement (OTM) mechanical forces trigger pseudo-inflammatory, osteoclastogenic and remodelling processes in the periodontal ligament (PDL) that are mediated by PDL fibroblasts via the expression of various signalling molecules. Thus far, it is unknown whether these processes are mainly induced by mechanical cellular deformation (mechanotransduction) or by concomitant hypoxic conditions via the compression of periodontal blood vessels. Human primary PDL fibroblasts were randomly seeded in conventional six-well cell culture plates with O-2-impermeable polystyrene membranes and in special plates with gas-permeable membranes (Lumox (R), Sarstedt), enabling the experimental separation of mechanotransducive and hypoxic effects that occur concomitantly during OTM. To simulate physiological orthodontic compressive forces, PDL fibroblasts were stimulated mechanically at 2 g.cm(-2) for 48 h after 24 h of pre-incubation. We quantified the cell viability by MTT assay, gene expression by quantitative real-time polymerase chain reaction (RT-qPCR) and protein expression by western blot/enzyme-linked immunosorbent assays (ELISA). In addition, PDL-fibroblast-mediated osteoclastogenesis (TRAP(+) cells) was measured in a 72-h coculture with RAW264.7 cells. The expression of HIF-1 alpha, COX-2, PGE2, VEGF, COL1A2, collagen and ALPL, and the RANKL/OPG ratios at the mRNA/protein levels during PDL-fibroblast-mediated osteoclastogenesis were significantly elevated by mechanical loading irrespective of the oxygen supply, whereas hypoxic conditions had no significant additional effects. The cellular-molecular mediation of OTM by PDL fibroblasts via the expression of various signalling molecules is expected to be predominantly controlled by the application of force (mechanotransduction), whereas hypoxic effects seem to play only a minor role. In the context of OTM, the hypoxic marker HIF-1 alpha does not appear to be primarily stabilized by a reduced O-2 supply but is rather stabilised mechanically