Antiferromagnetic and structural transitions in the superoxide KO2 from first principles: A 2p-electron system with spin-orbital-lattice coupling

KO2 exhibits concomitant antiferromagnetic (AFM) and structural transitions, both of which originate from the open-shell 2p electrons of O$_{2}^{-}$ molecules. The structural transition is accompanied by the coherent tilting of O$_{2}^{-}$ molecular axes. The interplay among the spin-orbital-lattice degrees of freedom in KO2 is investigated by employing the first-principles electronic structure theory and the kinetic-exchange interaction scheme. We have shown that the insulating nature of the high symmetry phase of KO2 at high temperature (T) arises from the combined effect of the spin-orbit coupling and the strong Coulomb correlation of O 2p electrons. In contrast, for the low symmetry phase of KO2 at low T with the tilted O$_{2}^{-}$ molecular axes, the band gap and the orbital ordering are driven by the combined effects of the crystal-field and the strong Coulomb correlation. We have verified that the emergence of the O 2p ferro-orbital ordering is essential to achieve the observed AFM structure for KO2

Electrochemical supercapacitors based on a novel graphene/conjugated polymer composite system

An efficient method for the preparation of a highly conducting hybrid material from graphene oxide nanosheets (GNS) and a novel conjugated polymer, poly(3,4-propylenedioxythiophene), is demonstrated. A functionalized monomer based on 3,4-propylenedioxythiophene, namely ProDOT-OH, was covalently functionalized with GNS, followed by oxidative polymerization to prepare GNS-f-PProDOT composites. The covalent functionalization process of GNS with the monomer ProDOT-OH was activated through the simple esterification reaction between the acyl chloride derivative on the nanosheets and the pendant hydroxyl group present in the monomer. Furthermore, the monomer functionalized GNS were co-polymerized with thiophene resulting in hybrid graphene nanostructures coated with highly conducting co-polymers with a room temperature electrical conductivity as high as 22.5 S cm(-1). The resulting hybrid materials were characterized using a range of analytical techniques. The specific capacitance value of the composite and the co-polymer hybrids at a scan rate of 10 mV s(-1) has been determined to be 158 and 201 F g(-1) respectively and hence particularly promising for supercapacitors.close232

Severe mitral regurgitation in a young female with pansinusitis and bronchiectasis

SummaryPrimary ciliary dyskinesia (PCD) is a disease characterized by symptoms of upper and lower respiratory tract infections due to abnormal structure and function of cilia.Cardiac involvement is characterized by situs inversus (Kartagener's syndrome in PCD) and other congenital cardiovascular abnormalities. We describe a 34-year-old female with a history of recurrent sinusitis and bronchiectasis but without situs inversus or other congenital cardiac anomalies in whom an association between mitral regurgitation secondary to myxoid degeneration and primary ciliary dyskinesia was suggested

Large clusters and hollow microfibers by multicomponent self-assembly of citrate stabilized gold nanoparticles with temperature-responsive amphiphilic dendrimers

Gold clusters with controlled sizes have been prepared by controlled self-assembly of citrate stabilized gold nanoparticles (AuNPs) with temperature-responsive luminescent amphiphilic dendrimers (Den 40) of oligo(p-phenylene vinylene) core branches and oligo(ethylene oxide) terminal chains. The shape and size of the resultant gold clusters depend strongly on the molar ratio of Den 40 to AuNPs. These gold clusters can further assemble into hollow microfibers decorated with AuNPs, which can be used as a promising substrate for surface enhanced Raman spectroscopy (SERS). The formation of spherical gold clusters and hollow microfibers simply by self-assembly of AuNPs and luminescent amphiphilic dendrimers (Den 40) could not only provide some useful insights for producing multifunctional materials via multicomponent self-assembly but also offer promise for potential applications of the self-assemblies in many systems, such as SERS and stimuli-responsive sensors.close2

Measurement of Blood Pressure Using an Arterial Pulsimeter Equipped with a Hall Device

To measure precise blood pressure (BP) and pulse rate without using a cuff, we have developed an arterial pulsimeter consisting of a small, portable apparatus incorporating a Hall device. Regression analysis of the pulse wave measured during testing of the arterial pulsimeter was conducted using two equations of the BP algorithm. The estimated values of BP obtained by the cuffless arterial pulsimeter over 5 s were compared with values obtained using electronic or liquid mercury BP meters. The standard deviation between the estimated values and the measured values for systolic and diastolic BP were 8.3 and 4.9, respectively, which are close to the range of values of the BP International Standard. Detailed analysis of the pulse wave measured by the cuffless radial artery pulsimeter by detecting changes in the magnetic field can be used to develop a new diagnostic algorithm for BP, which can be applied to new medical apparatus such as the radial artery pulsimeter