Quantum Tunneling of the Magnetic Moment in a Free Particle

We study tunneling of the magnetic moment in a particle that has full rotational freedom. Exact energy levels are obtained and the ground-state magnetic moment is computed for a symmetric rotor. The effect of the mechanical freedom on spin tunneling manifests itself in a strong dependence of the magnetic moment on the moments of inertia of the rotor. Energy of the particle exhibits quantum phase transitions between states with different values of the magnetic moment. Particles of various shapes are investigated and quantum phase diagram is obtained.Comment: 7 Figures, 5 Figure Captions, submitted to PR

Comparison of Glasgow Admission Prediction Score and Amb Score in predicting need for inpatient care.

AIM: We compared the abilities of two established clinical scores to predict emergency department (ED) disposition: the Glasgow Admission Prediction Score (GAPS) and the Ambulatory Score (Ambs). METHODS: The scores were compared in a prospective, multicentre cohort study. We recruited consecutive patients attending ED triage at two UK sites: Northern General Hospital in Sheffield and Glasgow Royal Infirmary, between February and May 2016. Each had a GAPS and Ambs calculated at the time of triage, with the triage nurses and treating clinicians blinded to the scores. Patients were followed up to hospital discharge. The ability of the scores to discriminate discharge from ED and from hospital at 12 and 48 hours after arrival was compared using the area under the curve (AUC) of their receiving-operator characteristics (ROC). RESULTS: 1424 triage attendances were suitable for analysis during the study period, of which 567 (39.8%) were admitted. The AUC for predicting admission was significantly higher for GAPS at 0.807 (95% CI 0.785 to 0.830), compared with 0.743 (95% CI 0.717 to 0.769) for Ambs, P12 hour and >48 hour. GAPS was also more accurate as a binary test, correctly predicting 1057 outcomes compared with 1004 for Ambs (74.2vs70.5%, P=0.012). CONCLUSION: The GAPS is a significantly better predictor of need for hospital admission than Ambs in an unselected ED population

Excited state dynamics of Zn–salophen complexes

Zn-salophen complexes are a promising class of fluorescent chemosensors for nucleotides and nucleic acids. We have investigated, by means of steady state UV-Vis, ultrafast transient absorption, fluorescence emission and time dependent density functional theory (TD-DFT) the behavior of the excited states of a salicylidene tetradentate Schiff base (Sal), its Zn(II) coordination compound (Zn-Sal) and the effect of the interaction between Zn-Sal and adenosine diphosphate (ADP). TD-DFT shows that the deactivation of the excited state of Sal occurs through torsional motion, due to its rotatable bonds and twistable angles. Complexation with Zn(II) causes rigidity so that the geometry changes in the excited states with respect to the ground state structure are minimal. By addition of ADP to a freshly prepared Zn-Sal ethanol solution, a longer relaxation constant, in comparison to Zn-Sal, was measured, indicative of the interaction between Zn-Sal and ADP. After a few days, the Zn-Sal-ADP solution displayed the same static and dynamic behavior of a solution containing only the Sal ligand, demonstrating that the coordination of the ADP anion to Zn(II)leads to the demetallation of the Sal ligand. Fluorescence measurements also revealed an enhanced fluorescence at 375 nm following the addition of ADP to the solution, caused by the presence of 2,3-diamino naphthalene that is formed by demetallation and partial decomposition of the Sal ligand. The efficient fluorescence of this species at 375 nm could be selectively detected and used as a probe for the detection of ADP in solution.[GRAPHICS]

Two-electron processes in multiple ionization under strong soft-x-ray radiation

In a combined experimental and theoretical study we have investigated the ionization of atomic argon upon irradiation with intense soft-x-ray pulses of 105 eV photon energy from the free-electron laser FLASH. The measured ion yields show charge states up to Ar7+. The comparison with the theoretical study of the underlying photoionization dynamics highlights the importance of excited states in general and of processes governed by electron correlation in particular, namely, ionization with excitation and shake-off, processes usually inaccessible by measurements of ionic yields only. The Ar7+ yield shows a clear deviation from the predictions of the commonly used model of sequential ionization via single-electron processes and the observed signal can only be explained by taking into account the full multiplet structure of the involved configurations and by inclusion of two-electron processes. The competing process of two-photon ionization from the ground state of Ar6+ is calculated to be orders of magnitude smaller

Plastic optical fibre sensor for spine bending monitoring

peer-reviewedThis paper presents a study on the application of plastic optical fibre for spine bending monitoring based on an intensity modulation. The bending angle is measured as the angle between the emitting and receiving fibres is changed. The measured light attenuation is compared with a theoretical evaluation and the differences between these values are discussed. It was found that the light attenuation for the light intensity agreed well (margin of error < 15%) with the theoretical value for the range between 180o (representing no bend) and 200o and it was significantly increased for the bending angle beyond that value due to the effect of fibre gap increment which resulted in a less reliable experimental estimation.PUBLISHEDpeer-reviewe

Induction of A9 dopaminergic neurons from neural stem cells improves motor function in an animal model of Parkinsons disease

Neural stem cells (NSCs) are widely endorsed as a cell source for replacement strategies in neurodegenerative disease. However, their usefulness is currently limited by the inability to induce specific neurotransmitter phenotypes in these cells. In order to direct dopaminergic neuronal fate, we overexpressed Pitx3 in NSCs that were then exposed to EII developing ventral mesencephalon (VM) in explant culture. This resulted in a significant potentiation of dopaminergic differentiation of the cells. When transplanted into the 6-hydroxydopamine lesioned Parkinsonian rats, these cografts of VM and Pitx3 overexpressing NSCs resulted in a significant restitution of motor function. In addition, there were greater numbers of Girk2 positive A9 neurons in the periphery of the transplants that were NSC derived. This demonstrates that given the correct signals, NSCs can be induced to become dopaminergic neurons that can differentiate into the correct nigrastriatal phenotype required for the treatment of Parkinsons disease