A water-soluble tetraazaperopyrene dye as strong G-quadruplex DNA binder

The interactions of the water-soluble tetraazaperopyrene dye 1 with ct-DNA, duplex-[(dAdT)12⋅(dAdT)12], duplex-[(dGdC)12⋅(dGdC)12] as well as with two G-quadruplex-forming sequences, namely the human telomeric 22AG and the promotor sequence c-myc, were investigated by means of UV/visible and fluorescence spectroscopy, isothermal titration calorimetry (ITC) and molecular docking studies. Dye 1 exhibits a high affinity for G-quadruplex structures over duplex DNA structures. Furthermore, the ligand shows promising G-quadruplex discrimination, with an affinity towards c-myc of 2×107 m−1 (i.e., Kd=50 nm), which is higher than for 22AG (4×106 m−1). The ITC data reveal that compound 1 interacts with c-myc in a stoichiometric ratio of 1:1 but also indicate the presence of two identical lower affinity secondary binding sites per quadruplex. In 22AG, there are two high affinity binding sites per quadruplex, that is, one on each side, with a further four weaker binding sites. For both quadruplex structures, the high affinity interactions between compound 1 and the quadruplex-forming nucleic acid structures are weakly endothermic. Molecular docking studies suggest an end-stacking binding mode for compound 1 interacting with quadruplex structures, and a higher affinity for the parallel conformation of c-myc than for the mixed-hybrid conformation of 22AG. In addition, docking studies also suggest that the reduced affinity for duplex DNA structures is due to the non-viability of an intercalative binding mode

Psychological correlates to dysfunctional eating patterns among morbidly obese patients accepted for bariatric surgery

Objective: To examine the relationships between dysfunctional eating patterns, personality, anxiety and depression in morbidly obese patients accepted for bariatric surgery. Design: The study used cross-sectional data collected in running a randomized controlled trial (http://clinicaltrials.gov/ct2/show/NCT01403558). Subjects: A total of 102 patients (69 women, 33 men) with a mean (SD) age of 42.6 (9.8) years and a mean BMI 43.5 (4.4) kg/m2 participated. Measurements: Measurements included the NEO PI-R (personality: neuroticism, extroversion, openness, conscientiousness and agreeableness), the TFEQ R-21 (dysfunctional eating: emotional eating (EE), uncontrolled eating (UE) and cognitive restraint of eating (CR) and the HADS (anxiety and depression). Results: The personality traits neuroticism and conscientiousness were more strongly correlated with dysfunctional eating compared with anxiety and depression. These differences were most pronounced for emotional and cognitive restraint of eating. Emotional eating occurred more often in female than male patients, a finding that was partially mediated by neuroticism but not by anxiety and depression. Conclusion: Personality traits may be important to address in the clinical management of morbidly obese patients seeking bariatric surgery as neuroticism is particularly salient in female patients displaying an emotional eating behaviour

The Detection and Location of Hydrido Ligands in High Nuclearity Osmium and Ruthenium Carbonyl Clusters: A Critical Survey

Hydrido carbonyl clusters represent powerful molecular models for the co-adsorption of carbon monoxide and hydrogen on metal surfaces, a key step in several catalytic processes. Over the past two decades a considerable number of such species have been reported in the literature. In this paper, the structural chemistry of high nuclearity osmium and ruthenium hydrido carbonyl clusters is critically reviewed. Particular emphasis is placed on the limits of the various indirect methods of hydride location in clusters, and an alternative interpretation of the results of spectroscopic studies performed for samples of some Ru and Os clusters in solution is given

Spectral Properties and Synchronization in Coupled Map Lattices

Spectral properties of Coupled Map Lattices are described. Conditions for the stability of spatially homogeneous chaotic solutions are derived using linear stability analysis. Global stability analysis results are also presented. The analytical results are supplemented with numerical examples. The quadratic map is used for the site dynamics with different coupling schemes such as global coupling, nearest neighbor coupling, intermediate range coupling, random coupling, small world coupling and scale free coupling.Comment: 10 pages with 15 figures (Postscript), REVTEX format. To appear in PR

Some generic aspects of bosonic excitations in disordered systems

We consider non-interacting bosonic excitations in disordered systems, emphasising generic features of quadratic Hamiltonians in the absence of Goldstone modes. We discuss relationships between such Hamiltonians and the symmetry classes established for fermionic systems. We examine the density \rho(\omega) of excitation frequencies \omega, showing how the universal behavior \rho(\omega) ~ \omega^4 for small \omega can be obtained both from general arguments and by detailed calculations for one-dimensional models

Accuracy of B(E2; 0+ -> 2+) transition rates from intermediate-energy Coulomb excitation experiments

The method of intermediate-energy Coulomb excitation has been widely used to determine absolute B(E2; 0+ -> 2+) quadrupole excitation strengths in exotic nuclei with even numbers of protons and neutrons. Transition rates measured with intermediate-energy Coulomb excitation are compared to their respective adopted values and for the example of 26Mg to the B(E2; 0+ -> 2+) values obtained with a variety of standard methods. Intermediate-energy Coulomb excitation is found to have an accuracy comparable to those of long-established experimental techniques.Comment: to be published in Phys. Rev.

Enhanced collectivity in 74Ni

The neutron-rich nucleus 74Ni was studied with inverse-kinematics inelastic proton scattering using a 74Ni radioactive beam incident on a liquid hydrogen targetat a center-of-mass energy of 80 MeV. From the measured de-excitation gamma-rays, the population of the first 2+ state was quantified. The angle-integrated excitation cross section was determined to be 14(4) mb. A deformation length of delta = 1.04(16) fm was extracted in comparison with distorted wave theory, which suggests that the enhancement of collectivity established for 70Ni continues up to 74Ni. A comparison with results of shell model and quasi-particle random phase approximation calculations indicates that the magic character of Z = 28 or N = 50 is weakened in 74Ni

Is the structure of 42Si understood?

A more detailed test of the implementation of nuclear forces that drive shell evolution in the pivotal nucleus \nuc{42}{Si} -- going beyond earlier comparisons of excited-state energies -- is important. The two leading shell-model effective interactions, SDPF-MU and SDPF-U-Si, both of which reproduce the low-lying \nuc{42}{Si}($2^+_1$) energy, but whose predictions for other observables differ significantly, are interrogated by the population of states in neutron-rich \nuc{42}{Si} with a one-proton removal reaction from \nuc{43}{P} projectiles at 81~MeV/nucleon. The measured cross sections to the individual \nuc{42}{Si} final states are compared to calculations that combine eikonal reaction dynamics with these shell-model nuclear structure overlaps. The differences in the two shell-model descriptions are examined and linked to predicted low-lying excited $0^+$ states and shape coexistence. Based on the present data, which are in better agreement with the SDPF-MU calculations, the state observed at 2150(13)~keV in \nuc{42}{Si} is proposed to be the ($0^+_2$) level.Comment: accepted in Physical Review Letter