Intrapartum fetal heart rate monitoring: using audit methodology to identify areas for research and practice improvement

The purpose of the study was to explore the fetal heart rate monitoring practices of midwives and doctors to determine compliance with an evidence-based guideline for fetal heart rate monitoring endorsed by one New Zealand (NZ) District Health Board (DHB). A retrospective audit of 193 randomly selected medical records was undertaken over six months (July-December 2006). The audit revealed deficiencies in choice of fetal heart rate monitoring modality, monitoring technique, documentation, communication and use of a standardised approach and language for interpreting cardiotocograph (CTG) traces especially the description and categorisation of the four main fetal heart rate features. Multidisciplinary education and a standardised template for reporting CTG's were key recommendations

Severe “sweet” pleural effusion in a continuous ambulatory peritoneal dialysis patient

AbstractIntroductionHydrothorax is a rare complication of continuous ambulatory peritoneal dialysis (CAPD) which can progress quickly to cause acute respiratory distress.Case presentationWe present a 76 year-old female with a past medical history significant for end-stage renal disease (ESRD) on daily home peritoneal dialysis for 2 years presented to the hospital from home with shortness of breath at rest and cough for 2 days prior to admission. She developed severe respiratory distress and had emergent pleurocentesis that released 3.8 L of pleural fluid. The analysis showed significantly high sugar indicative of hydrothorax from CAPD. She underwent thoracotomy with pleurodesis and switched to hemodialysis for 6 weeks before resuming CAPD.ConclusionA high glucose concentration in the pleural fluid is pathognomonic for hydrothorax from dialysis fluid after rule out other possible causes of pleural effusion. Patients who are on CAPD presenting with marked pleural effusion should prompt clinicians to consider the differential diagnosis of pleuroperitoneal communications

Auscultation - The Action of Listening

The article focuses on the historical development of auscultation and listening to fetal heart beats. It mentions that auscultation defines as the action of listening to the sounds inside the body. It says that the use stethoscope in midwifery practice was introduced in 1819 wherein listening to fetal heart sounds helps determine the well-being of the fetus. It adds that intermittent auscultation was recommended for fetal heart monitoring by the professional evidence-based guidelin

Classical percolation fingerprints in the high-temperature regime of the integer quantum Hall effect

We have performed magnetotransport experiments in the high-temperature regime (up to 50 K) of the integer quantum Hall effect for two-dimensional electron gases in semiconducting heterostructures. While the magnetic field dependence of the classical Hall law presents no anomaly at high temperatures, we find a breakdown of the Drude-Lorentz law for the longitudinal conductance beyond a crossover magnetic field B_c ~ 1 T, which turns out to be correlated with the onset of the integer quantum Hall effect at low temperatures. We show that the high magnetic field regime at B > B_c can be understood in terms of classical percolative transport in a smooth disordered potential. From the temperature dependence of the peak longitudinal conductance, we extract scaling exponents which are in good agreement with the theoretically expected values. We also prove that inelastic scattering on phonons is responsible for dissipation in a wide temperature range going from 1 to 50 K at high magnetic fields.Comment: 14 pages + 8 Figure

Heat transport in Bi_{2+x}Sr_{2-x}CuO_{6+\delta}: departure from the Wiedemann-Franz law in the vicinity of the metal-insulator transition

We present a study of heat transport in the cuprate superconductor Bi_{2+x}Sr_{2-x}CuO_{6+\delta} at subkelvin temperatures and in magnetic fields as high as 25T. In several samples with different doping levels close to optimal, the linear-temperature term of thermal conductivity was measured both at zero-field and in presence of a magnetic field strong enough to quench superconductivity. The zero-field data yields a superconducting gap of reasonable magnitude displaying a doping dependence similar to the one reported in other families of cuprate. The normal-state data together with the results of the resistivity measurements allows us to test the Wiedemann-Franz(WF) law, the validity of which was confirmed in an overdoped sample in agreement with previous studies. In contrast, a systematic deviation from the WF law was resolved for samples displaying either a lower doping content or a higher disorder. Thus, in the vicinity of the metal-insulator cross-over, heat conduction in the zero-temperature limit appears to become significantly larger than predicted by the WF law. Possible origins of this observation are discussed.Comment: 9 pages including 7 figures, submitted to Phys. Rev.

Magnetotransport in graphene on silicon side of SiC

We have studied the transport properties of graphene grown on silicon side of SiC. Samples under study have been prepared by two different growth methods in two different laboratories. Magnetoresistance and Hall resistance have been measured at temperatures between 4 and 100 K in resistive magnet in magnetic fields up to 22 T. In spite of differences in sample preparation, the field dependence of resistances measured on both sets of samples exhibits two periods of magneto-oscillations indicating two different parallel conducting channels with different concentrations of carriers. The semi-quantitative agreement with the model calculation allows for conclusion that channels are formed by high-density and low-density Dirac carriers. The coexistence of two different groups of carriers on the silicon side of SiC was not reported before.Comment: 5 pages, 6 figures, accepted for publication in the "IOP Journal of Physics: Conference series" as a contribution to the proceedings of the 20th International Conference on "High Magnetic Fields in Semiconductor Physics", HMF 2

Ultrahigh magnetic field spectroscopy reveals the band structure of the 3D topological insulator Bi2_2Se3_3

We have investigated the band structure at the $\Gamma$ point of the three-dimensional (3D) topological insulator Bi$_2$Se$_3$ using magneto-spectroscopy over a wide range of energies ($0.55-2.2$\,eV) and in ultrahigh magnetic fields up to 150\,T. At such high energies ($E>0.6$\,eV) the parabolic approximation for the massive Dirac fermions breaks down and the Landau level dispersion becomes nonlinear. At even higher energies around 0.99 and 1.6 eV, new additional strong absorptions are observed with a temperature and magnetic-field dependence which suggest that they originate from higher band gaps. Spin orbit splittings for the further lying conduction and valence bands are found to be 0.196 and 0.264 eV

Magneto-resistance quantum oscillations in a magnetic two-dimensional electron gas

Magneto-transport measurements of Shubnikov-de Haas (SdH) oscillations have been performed on two-dimensional electron gases (2DEGs) confined in CdTe and CdMnTe quantum wells. The quantum oscillations in CdMnTe, where the 2DEG interacts with magnetic Mn ions, can be described by incorporating the electron-Mn exchange interaction into the traditional Lifshitz-Kosevich formalism. The modified spin splitting leads to characteristic beating pattern in the SdH oscillations, the study of which indicates the formation of Mn clusters resulting in direct anti-ferromagnetic Mn-Mn interaction. The Landau level broadening in this system shows a peculiar decrease with increasing temperature, which could be related to statistical fluctuations of the Mn concentration.Comment: 8 pages, 6 figure

Influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors

In a recent paper [B. A. Piot et al., Phys. Rev. B 72, 245325 (2005)], we have shown that the lifting of the electron spin degeneracy in the integer quantum Hall effect at high filling factors should be interpreted as a magnetic-field-induced Stoner transition. In this work, we extend the analysis to investigate the influence of the single-particle Zeeman energy on the quantum Hall ferromagnet at high filling factors. The single-particle Zeeman energy is tuned through the application of an additional in-plane magnetic field. Both the evolution of the spin polarization of the system and the critical magnetic field for spin splitting are well described as a function of the tilt angle of the sample in the magnetic field.Comment: Published in Phys. Rev.