Multifractal analysis of the electronic states in the Fibonacci superlattice under weak electric fields

Influence of the weak electric field on the electronic structure of the Fibonacci superlattice is considered. The electric field produces a nonlinear dynamics of the energy spectrum of the aperiodic superlattice. Mechanism of the nonlinearity is explained in terms of energy levels anticrossings. The multifractal formalism is applied to investigate the effect of weak electric field on the statistical properties of electronic eigenfunctions. It is shown that the applied electric field does not remove the multifractal character of the electronic eigenfunctions, and that the singularity spectrum remains non-parabolic, however with a modified shape. Changes of the distances between energy levels of neighbouring eigenstates lead to the changes of the inverse participation ratio of the corresponding eigenfunctions in the weak electric field. It is demonstrated, that the local minima of the inverse participation ratio in the vicinity of the anticrossings correspond to discontinuity of the first derivative of the difference between marginal values of the singularity strength. Analysis of the generalized dimension as a function of the electric field shows that the electric field correlates spatial fluctuations of the neighbouring electronic eigenfunction amplitudes in the vicinity of anticrossings, and the nonlinear character of the scaling exponent confirms multifractality of the corresponding electronic eigenfunctions.Comment: 10 pages, 9 figure

Nutlin-3, the small-molecule inhibitor of MDM2, promotes senescence and radiosensitises laryngeal carcinoma cells harbouring wild-type p53

BACKGROUND: Primary radiotherapy (RT) is a mainstay of treatment for laryngeal squamous cell carcinoma (LSCC). Although the cure rates for early (T1) vocal cord tumours are high, RT proves ineffective in up to a third of T3 carcinomas. Moreover, RT is associated with debilitating early- and late-treatment-related toxicity, thus finding means to de-escalate therapy, while retaining/augmenting therapeutic effectiveness, is highly desirable. p53 is a key mediator of radiation responses; we therefore investigated whether Nutlin-3, a small-molecule inhibitor of MDM2 (mouse double minute 2; an essential negative regulator of p53), might radiosensitise LSCC cells. METHODS: We performed clonogenic assays to measure radiosensitivity in a panel of LSCC cell lines (for which we determined p53 mutational status) in the presence and absence of Nutlin-3. RESULTS: LSCC cells harbouring wild-type p53 were significantly radiosensitised by Nutlin-3 (P<0.0001; log-rank scale), and displayed increased cell cycle arrest and significantly increased senescence (P<0.001) in the absence of increased apoptosis; thus, our data suggest that senescence may mediate this increased radiosensitivity. CONCLUSION: This is the first study showing Nutlin-3 as an effective radiosensitiser in LSCC cells that retain wild-type p53. The clinical application of Nutlin-3 might improve local recurrence rates or allow treatment de-escalation in these patients

Identification of 12 new susceptibility loci for different histotypes of epithelial ovarian cancer.

To identify common alleles associated with different histotypes of epithelial ovarian cancer (EOC), we pooled data from multiple genome-wide genotyping projects totaling 25,509 EOC cases and 40,941 controls. We identified nine new susceptibility loci for different EOC histotypes: six for serous EOC histotypes (3q28, 4q32.3, 8q21.11, 10q24.33, 18q11.2 and 22q12.1), two for mucinous EOC (3q22.3 and 9q31.1) and one for endometrioid EOC (5q12.3). We then performed meta-analysis on the results for high-grade serous ovarian cancer with the results from analysis of 31,448 BRCA1 and BRCA2 mutation carriers, including 3,887 mutation carriers with EOC. This identified three additional susceptibility loci at 2q13, 8q24.1 and 12q24.31. Integrated analyses of genes and regulatory biofeatures at each locus predicted candidate susceptibility genes, including OBFC1, a new candidate susceptibility gene for low-grade and borderline serous EOC

Impact of IL28B polymorphism on treatment induced viral clearance in HCV infected Egyptian patients

Background and objective: Interleukin (IL) 28B single nucleotide polymorphisms (SNP) was recently recognized as predictor of SVR in HCV infected patients treated by combination therapy of pegylatedinterferon (Peg-IFN) and ribavirin (RBV). The aim of the current study was to assess IL 28B polymorphism SNP (rs12979860) as a predictor of response to combined Peg-INF/RBV therapy in Egyptian chronic HCV infected patients.Design and methods: The study was conducted on 247 HCV infected patients and 100 apparently healthy control subjects. All patients were treated with PEG-IFN-α/ribavirin; and they were classified according to their response to treatment. Genotyping of IL28B rs12979860 was performed on peripheral blood DNA using polymerase chain reactionrestriction fragment length polymorphism (PCR-RFLP) assay.Results: The overall frequency of IL28B genotypes was 24.7%, 50.2% and 25.1% for genotypes CC, CT and TT respectively, while the response rate was 82%, 38.7% and 43.8% for genotypes CC, CT and TT respectively, moreover, genotype CC had increased probability to HCV clearance than both genotypes CT and TT with OR 7.71 (95%CI: 3.71-15.79).Conclusion: Genotyping of IL28B at SNP rs12979860 could be used as a guide to tailor treatment in Egyptian patients infected with HCV for better outcome.Key wards: Hepatitis C virus, Pegylated-interferon, ribavirin, sustained virological response, IL28

Faisabilité et croissance avec haute reproductibilité de multicouches métalliques à magnétorésistance géante par pulvérisation diode RF

Les objectifs du présent travail sont de deux ordres : d'abord obtenir le rapport de MRG, ΔR/R, le plus élevé dans des multicouches Co/Cu élaborées à partir du procédé inhabituel de pulvérisation par diode radiofréquence (RF). En second, analyser les corrélations entre la MRG d'une part et les textures et rugosités interfaciales déduites des diffractions X aux petits et grands angles et de la microscopie à force atomique (MFA) d'autre part. A cet effet, nous avons cherché à induire différentes structures interfaciales en modifiant les paramètres de pulvérisation (pression du gaz pulvérisant PAr) ce qui, par ailleurs, a permis de définir les conditions optimales de dépôt pour l'obtention d'une MRG élevée. L'influence de l'épaisseur tCo du film Co a été étudiée pour une épaisseur du film de Cu = 9Å correspondant au premier maximum de la dépendance oscillatoire avec tCu du rapport de MRG. De ces résultats, nous concluons que le paramètre pertinent est la rugosité interfaciale qui induit un effet important à la fois sur la MRG et sur la résistivité des super-réseaux. Un changement de pente de Rs-1 en fonction de t2Co est attribué à une augmentation de l'effet de rugosité quand tCo décroît de l'échelle mésoscopique (tCo> 25Å) vers l'échelle nanoscopique (tCo< 25Å)

Unlocking Bloch-type chirality in ultrathin magnets through uniaxial strain

Chiral magnetic domain walls are of great interest because lifting the energetic degeneracy of left- and right-handed spin textures in magnetic domain walls enables fast current-driven domain wall propagation. Although two types of magnetic domain walls are known to exist in magnetic thin films, Bloch- and Néel-walls, up to now the stabilization of homochirality was restricted to Néel-type domain walls. Since the driving mechanism of thin-film magnetic chirality, the interfacial Dzyaloshinskii-Moriya interaction, is thought to vanish in Bloch-type walls, homochiral Bloch walls have remained elusive. Here we use real-space imaging of the spin texture in iron/nickel bilayers on tungsten to show that chiral domain walls of mixed Bloch-type and Néel-type can indeed be stabilized by adding uniaxial strain in the presence of interfacial Dzyaloshinskii-Moriya interaction. Our findings introduce Bloch-type chirality as a new spin texture, which may open up new opportunities to design spin-orbitronics devices