Theory and modeling of molecular modes in the NMR relaxation of fluids

Traditional theories of the NMR autocorrelation function for intramolecular dipole pairs assume single-exponential decay, yet the calculated autocorrelation of realistic systems display a rich, multi-exponential behavior resulting in anomalous NMR relaxation dispersion (i.e., frequency dependence). We develop an approach to model and interpret the multi-exponential autocorrelation using simple, physical models within a rigorous statistical mechanical development that encompasses both rotational and translational diffusion in the same framework. We recast the problem of evaluating the autocorrelation in terms of averaging over a diffusion propagator whose evolution is described by a Fokker-Planck equation. The time-independent part admits an eigenfunction expansion, allowing us to write the propagator as a sum over modes. Each mode has a spatial part that depends on the specified eigenfunction, and a temporal part that depends on the corresponding eigenvalue (i.e., correlation time) with a simple, exponential decay. The spatial part is a probability distribution of the dipole-pair, analogous to the stationary states of a quantum harmonic oscillator. Drawing inspiration from the idea of inherent structures in liquids, we interpret each of the spatial contributions as a specific molecular mode. These modes can be used to model and predict NMR dipole-dipole relaxation dispersion of fluids by incorporating phenomena on the molecular level. We validate our statistical mechanical description of the distribution in molecular modes with molecular dynamics simulations interpreted without any relaxation models or adjustable parameters: the most important poles in the Pad{\'e}-Laplace transform of the simulated autocorrelation agree with the eigenvalues predicted by the theory

Morphological, anatomical and palynological study of centaurea calcitrapa L. ssp. cilicica (Boiss. & Bal.) Wagenitz and centaurea solstitialis L. ssp. carneola (Boiss.) Wagenitz endemic for Turkey

In this study, morphological, anatomical and palynological properties of Centaurea calcitrapa L. ssp. cilicica (Boiss. & Bal.) Wagenitz and C. solstitialis L. ssp. carneola (Boiss.) Wagenitz which are endemic for Turkey were investigated. In the morphological studies, the properties of these endemic subspecies were determined and measurements made on the materials and compared with floristic-systematical references. The morphology of capitula, involucra, involucral leaves (phyllaries) and achene have been investigated. In the anatomical studies; the transverse sections were taken from the root, stem, phyllaries and leaves of the subspecies. In the palynological researches Polar diameter, equatorial length and apertures were measured in detailed. Microphotographs of pollen and anatomical structures are also presented

Arrhythmic effects of Ivabradine in patients with coronary artery disease

Objectives: Ivabradine is the first specific heart rate-lowering agent that has completed clinical development for stable angina pectoris. The aim of the present study was to investigate the effects of ivabradine therapy on P-wave duration, dispersion and QT duration, dispersion in coronary artery disease patients. Methods and Results: The study population consisted of 21 patients with CAD who have confirmed by coronary angiography previously. Written informed consent was obtained in all patients. Twelve-lead electrocardiogram was recorded for each subject at a rate of 50mm/s on admission and repeated after 1 month ivabradine therapy. QT duration, QT dispertion, maximum and minimum QT duration calculated. Maximum and minimum P wave and P wave dispersion has been calculated. Heart rate was decreased after ivabradine therapy. (75±15 and 63±10, P=0.02).There was no difference between Pmax, Pmin and Pdis values before and after treatment. QTmax value was prolonged after treatment. (410±43 and 431±14, P=0,005) but there was no difference between cQTmax value.(455±38 and 439±21) There was no difference between QTdis and cQTdis values before and after treatment. (44±18 & 49±14; and 49±22 & 48±15). QTmax was prolonged after ivabradine therapy but cQTmax, Pdis, QTdis and cQTdis were not prolonged. Conclusion: There is no relationship between ivabradine therapy and increased risk of ventricular and atrial arrhythmia in coronary artery disease patient

Analysis of a new simple one dimensional chaotic map

In this paper, a new one-dimensional map is introduced, which exhibits chaotic behavior in small interval of real numbers. It is discovered that a very simple fraction in a square root with one variable and two parameters can lead to a period-doubling bifurcations. Given the nonlinear dynamics of one-dimensional chaotic maps, it is usually seen that chaos arises when the parameter raises up to a value, however in our map, which seems reverse, it arises when the related parameter decreases and approaches to a constant value. Since proposing a new map entails solid foundations, the analysis is originated with linear stability analysis of the new map, finding fixed points. Additionally, the nonlinear dynamics analysis of the new map also includes cobweb plot, bifurcation diagram, and Lyapunov analysis to realize further dynamics. This research is mainly consisting of real numbers, therefore imaginary parts of the simulations are omitted. For the numerical analysis, parameters are assigned to given values, yet a generalized version of the map is also introduced