Brillouin Scattering Study of Ferroelectric Instability of Calcium-Strontium-Barium Niobate Single Crystals.

Uniaxial ferroelectrics with tetragonal tungsten bronze structure are important functional materials with photorefractive, electrooptic, piezoelectric, and pyroelectric properties. SrBaNbO (SBN100) with > 50 is known as a typical uniaxial relaxor ferroelectric, while CaBaNbO (CBN100) undergoes nearly normal ferroelectric phase transitions. Single crystals of CSBN100 = [(CBN28) + (1 - ) (SBN61)] = CaBaNbO + (1 - ) SrBaNbO with nominal = 0.

Right Ventricular Index for Risk Stratification of Patients with Pulmonary Arterial Hypertension.

Background: Right ventricular (RV) dysfunction is a major prognostic predictor in pulmonary arterial hypertension (PAH).

Objectives: The objective of this study was to assess the prognostic impact of a newly developed index merging haemodynamic parameters into 1 variable.

Methods: We retrospectively assessed 2 cohorts of 248 patients (164 from Hamburg and 84 from Heidelberg) with invasively diagnosed PAH.

Electric field and aging effects of uniaxial ferroelectrics Sr Ba NbO probed by Brillouin scattering.

Static and dynamic heterogeneity of disordered system is one of the current topics in materials science. In disordered ferroelectric materials with random fields, dynamic polar nanoregions (PNRs) appear at Burns temperature and freeze into nanodomain state below Curie temperature (T ). This state is very sensitive to external electric field and aging by which it gradually switches into macrodomain state.

Large Electrocaloric Effect in Relaxor Ferroelectric and Antiferroelectric Lanthanum Doped Lead Zirconate Titanate Ceramics.

Both relaxor ferroelectric and antiferroelectric materials can individually demonstrate large electrocaloric effects (ECE). However, in order to further enhance the ECE it is crucial to find a material system, which can exhibit simultaneously both relaxor ferroelectric and antiferroelectric properties, or easily convert from one into another in terms of the compositional tailoring. Here we report on a system, in which the structure can readily change from antiferroelectric into relaxor ferroelectric and vice versa.

Electric in-plane polarization in multiferroic CoFe₂O₄/BaTiO₃ nanocomposite tuned by magnetic fields.

Ferrimagnetic CoFe2O4 nanopillars embedded in a ferroelectric BaTiO3 matrix are an example for a two-phase magnetoelectrically coupled system. They operate at room temperature and are free of any resource-critical rare-earth element, which makes them interesting for potential applications. Prior studies succeeded in showing strain-mediated coupling between the two subsystems.

Coexistence of antiferromagnetic and spin cluster glass order in the magnetoelectric relaxor multiferroic PbFe 0.5 Nb 0.5 O3.

The coexistence of cluster glass with long-range antiferromagnetic order in the relaxor ferroelectric PbFe 0.5 Nb 0.5 O3 is elucidated.

Multiferroic and magnetoelectric materials--novel developments and perspectives.

Magnetoelectric (ME) materials are of utmost interest in view of both fundamental understanding and novel desirable applications. Despite its smallness, the linear ME effect has been shown to control spintronic devices very efficiently, e.g.

Petechial bleedings in sudden infant death.

The autopsy reports of 484 cases of deceased infants (201 females, 283 males) were analysed retrospectively for the existence of external and internal petechial bleedings (PET). The cases were divided into five groups on the basis of the cause of death (sudden infant death syndrome, sepsis, airway infections, asphyxia and trauma). Internal PET (pleural, pericardial, epicardial, thymic and peritoneal) were observed in each group with a lower prevalence in cases of trauma.

The German case-control scene investigation study on SIDS: epidemiological approach and main results.

The present study, which was part of the German SIDS Study (GeSID), enrolled sudden infant death syndrome (SIDS) cases and population controls and obtained objective scene data via specifically trained observers shortly after discovery of each dead infant. Infants who had died suddenly and unexpectedly at ages between 8 and 365 days were enrolled in five regions of Germany between November 1998 and October 2001. Shortly after discovery of each dead infant, a specially trained doctor of legal medicine visited the bereaved family at home.

(Sr,Mn)TiO3: a magnetoelectric multiglass.

By close analogy with multiferroic materials with coexisting long-range electric and magnetic orders a "multiglass" scenario of two different glassy states is observed in Sr(0.98)Mn(0.02)TiO(3) ceramics.

Superconducting quantum interference device setup for magnetoelectric measurements.

A commercial superconducting quantum interference device (SQUID) setup (MPMS 5S from Quantum Design), equipped with a magnetic ac susceptibility option, is modified for measurements of the linear magnetoelectric (ME) effect, i.e., of the magnetic moment induced by an applied external electric field in a ME sample.

Modes of periodic domain wall motion in ultrathin ferromagnetic layers.

Magnetization reversal in a periodic magnetic field is studied on an ultrathin, ultrasoft ferromagnetic Pt/Co(0.5 nm)/Pt trilayer exhibiting weak random domain wall (DW) pinning. The DW motion is imaged by polar magneto-optic Kerr effect microscopy and monitored by superconducting quantum interference device susceptometry.

Computer-controlled susceptometer for investigating the linear and nonlinear dielectric response.

A fully automatized alternating current (ac) susceptometer is constructed for simultaneous measurements of the phase resolved complex linear and complex nonlinear ac susceptibilities of lossy and dispersive dielectric materials. This relatively simple setup allows measurements over a wide range of experimental variables, such as ac amplitudes up to 40 V, frequencies from 10(-2) to 10(3) Hz, and temperatures from 100 to 600 K utilizing only current/voltage and analog/digital converters and a personal computer. In contrast with the commonly used analysis of the charge accumulated on a standard capacitor in series with the sample our method is based on the analysis of the current flowing directly through the sample.

Evolution of nanodomains in the uniaxial relaxor Sr0.61Ba0.39Nb2O6:Ce.

The evolution of the nanodomain pattern of the uniaxial relaxor ferroelectric strontium barium niobate doped with cerium was studied by piezoresponse force microscopy (PFM). The fractal-like nanodomains observed at room temperature decay on heating. At temperatures up to about 15 K above the Curie temperature, Tc = 320 K, areas of correlated polarization are still visible.

Two-dimensional Ising model criticality in a three-dimensional uniaxial relaxor ferroelectric with frozen polar nanoregions.

The charge-disordered three-dimensional uniaxial relaxor ferroelectric Sr0.61Ba0.39Nb2O6 splits up into metastable polar nanoregions and paraelectric interfaces upon cooling from above Tc.

Increased polysialic acid neural cell adhesion molecule expression in human hippocampus of heroin addicts.

Chronic exposure to heroin is known to cause cognitive deficits. However, little is known about the underlying molecular mechanisms. It has been suggested that opiate-induced neurotoxicity as well as impaired plasticity and regeneration may be relevant.

Evaluation of the correlation between time corpses spent in in-ground graves and findings at exhumation.

To determine how long pathological findings persist after burial and which factors play a role in decomposition of a corpse, we evaluated all bodies exhumed under the auspices of the Institute of Legal Medicine at the Hannover Medical School between 1978 and 1997. A total of 87 exhumations (54 men, 33 women) were performed in this period. The time bodies remained buried varied between 5 days and 16.

Y-SNP-genotyping - a new approach in forensic analysis.

Y-chromosomal DNA polymorphisms, especially Y-STRs are well established in forensic routine case work. The STRs are used for identification in paternity deficiency cases and stain analysis with complicate mixtures of male and female DNA. In contrast, Y-chromosomal SNPs are a new tool in forensic investigations.

[Examination of live victims of violent crimes at the Institutes of Legal Medicine of Hanover, Cologne and Leipzig].

During the last few years the importance of clinical forensic medicine has increased within the field itself, but also in interdisciplinary cooperation. Although examinations of live victims play a substantial role in the every-day work of most German forensic scientists, the number of data published on their frequency and the type of offence for which they were performed is small. For this reason a comparison of the data from the Institutes of Legal Medicine in Hanover, Cologne and Leipzig was carried out.

Population data of Y-chromosomal STRs in Russian males of the Primorye region population.

Data of eight Y-chromosomal STRs, the so called "minimal core set", were obtained from 152 unrelated males of the Primorye region of Russia. The allelic frequencies correspond to other European populations. The background is a settlement of males from the European part of Russia, Ukraine and other states which were included in the former western part of the Soviet Union.

Creep and relaxation dynamics of domain walls in periodically poled KTiOPO4.

Creep and relaxation of domain walls under ac electric fields are observed in an ideal model system, periodically poled KTiOPO4, to occur in different regimes, which are separated by dynamic phase transitions at frequencies f(m)(T)=f(m0)exp((-DeltaE/k(B)T), with f(m0)=3 x 10(9) Hz and DeltaE=0.6 eV. Power law dispersion of the creep susceptibility, chi proportional to 1+(iomegatau)(-beta), with beta approximately equal to 0.

The lingual tonsillar hyperplasia in relation to unanticipated difficult intubation: is there any relationship between lingual tonsillar hyperplasia and tonsillectomy?

The lingual tonsillar hyperplasia (LTH) is a rare and dangerous condition of the upper airway because it is one of several risks during intubation which can cause serious complications like cardiac arrest, cerebral anoxia, and death. The LTH is rarely detectable during a routine oropharyngeal examination. The lingual tonsil is of particular interest to forensic medicine to assess cases with malpractice in connection with intubation difficulties.