2D layered transport properties from topological insulator Bi2Se3 single crystals and micro flakes.

Low-field magnetotransport measurements of topological insulators such as Bi2Se3 are important for revealing the nature of topological surface states by quantum corrections to the conductivity, such as weak-antilocalization. Recently, a rich variety of high-field magnetotransport properties in the regime of high electron densities (∼10(19) cm(-3)) were reported, which can be related to additional two-dimensional layered conductivity, hampering the identification of the topological surface states. Here, we report that quantum corrections to the electronic conduction are dominated by the surface states for a semiconducting case, which can be analyzed by the Hikami-Larkin-Nagaoka model for two coupled surfaces in the case of strong spin-orbit interaction.

Large local Hall effect in pin-hole dominated multigraphene spin-valves.

We report local and non-local measurements in pin-hole dominated mesoscopic multigraphene spin-valves. Local spin-valve measurements show spurious switching behavior in resistance during magnetic field sweeping similar to the signal observed due to spin injection into multigraphene. The switching behavior has been explained in terms of a local Hall effect due to a thickness irregularity of the tunnel barrier.

The influence of Ga(+) irradiation on the transport properties of mesoscopic conducting thin films.

We studied the influence of 30 keV Ga(+)-ions-commonly used in focused-ion-beam (FIB) devices-on the transport properties of thin crystalline graphite flakes, and La(0.7)Ca(0.3)MnO(3) and Co thin films.

Frequency of visits for health care by low-birth-weight and preterm Saudi infants in the first year of life.

A retrospective hospital-based cross-sectional survey in a Saudi Arabian hospital compared the frequency of visits to hospital of low-birth-weight and normal-birth-weight infants and of preterm and full-term infants during the first year of life. A multivariate analysis of the visits for health care with birth weight, term, Apgar score, mode of delivery and sex was made for 1892 infants. The number of visits for health care was significantly higher for low-birth-weight and preterm infants.

Human brucellosis in Northern Saudi Arabia.

Objectives: Analysis of the clinical features, laboratory findings, treatment given and complications seen in brucellosis patients at the Northern Area Armed Forces Hospital, Hafr Al-Batin, Kingdom of Saudi Arabia.

Methods: We retrieved and reviewed the record charts of all patients from January 1995 to December 2001 with a clinical diagnosis of brucellosis whose brucella agglutination titre was 1:160 or greater from the Medical Records Department of Northern Area Armed Forces Hospital, Hafr Al-Batin. We extracted from the files the information on age, gender, occupation, history of raw milk or milk products ingestion, presenting symptoms and physical signs.