Scaphotrapezial ligament: normal arthro-CT and arthro-MRI appearance with anatomical and clinical correlation.

The purpose of our study was to demonstrate and describe the MR and arthro-CT anatomic appearance of the scaphotrapezial ligament and illustrate some of the pathologies involving this structure. This ligament consists of two slips that originate from the radiopalmar aspect of the scaphoid tuberosity and extend distally, forming a V shape. The ulnar fibers, which are just radial to the flexor carpi radialis sheath, inserted along the trapezial ridge. The radial fibers were found to be thinner and inserted at the radial aspect of the trapezium. Twelve fresh cadaver wrists were dissected, with close attention paid to the scaphotrapezio-trapezoidal (STT) joint. An osseoligamentous specimen was dissected with removal of all musculotendinous structures around the STT joint and was performed with high-resolution acquisition in a 128-MDCT scanner. Samples of the wrist area were collected from two fetal specimens. A retrospective study of 55 patients with wrist pain that were submitted to arthrography, arthro-CT, and arthro-MRI imaging was performed (10 patients on a 3-T superconducting magnet and 45 patients on a 1.5-T system). Another ten patients had high-resolution images on a 3-T superconducting magnet without arthrographic injection. MR arthrography and arthro-CT improved visualization and provided detailed information about the anatomy of the scaphotrapezial ligament. Knowledge of the appearance of this normal ligament on MRI allows accurate diagnosis of lesions and will aid when surgery is indicated or may have a role in avoiding unnecessary immobilization.

Multiband superconductivity in the Chevrel phases SnMo6S8 and PbMo6S8.

Sub-Kelvin scanning tunneling spectroscopy in the Chevrel phases SnMo6S8 and PbMo6S8 reveals two distinct superconducting gaps with Δ1=3 meV, Δ2∼1.0 meV and Δ1=3.1 meV, Δ2∼1.4 meV, respectively. The gap distribution is strongly anisotropic, with Δ2 predominantly seen when scanning across unit-cell steps on the (001) sample surface. The spectra are well fitted by an anisotropic two-band BCS s-wave gap function. Our spectroscopic data are confirmed by electronic heat capacity measurements, which also provide evidence for a twin-gap scenario.

Nernst and Seebeck coefficients of the cuprate superconductor YBa2Cu3O6.67: a study of Fermi surface reconstruction.

The Seebeck and Nernst coefficients S and nu of the cuprate superconductor YBa{2}Cu{3}O{y} (YBCO) were measured in a single crystal with doping p=0.12 in magnetic fields up to H=28 T. Down to T=9 K, nu becomes independent of field by H approximately 30 T, showing that superconducting fluctuations have become negligible. In this field-induced normal state, S/T and nu/T are both large and negative in the T-->0 limit, with the magnitude and sign of S/T consistent with the small electronlike Fermi surface pocket detected previously by quantum oscillations and the Hall effect. The change of sign in S(T) at T approximately 50 K is remarkably similar to that observed in La2-xBaxCuO4, La{2-x-y}Nd{y}Sr_{x}CuO{4}, and La{2-x-y}Eu{y}Sr{x}CuO{4}, where it is clearly associated with the onset of stripe order. We propose that a similar density-wave mechanism causes the Fermi surface reconstruction in YBCO.

Real-space vortex glass imaging and the vortex phase diagram of SnMo6S8.

Using scanning tunneling microscopy at 400 mK, we have obtained maps of around 100 vortices in SnMo(6)S(8) from 2-9 T. The orientational and positional disorder at 5 and 9 T show that these are the first large-scale images of a vortex glass. At higher temperature a magnetization peak effect is observed, whose upper boundary coincides with a lambda anomaly in the specific heat. Our data favor a kinetic glass description of the vortex melting transition, indicating that vortex topological disorder persists at fields and temperatures far below the peak effect in low-T(c) superconductors.

[Prevalence of reported child abuse by parents in a pediatric out-patient population]. / Prevalência de violência física relatada contra crianças em uma população de ambulatório pediátrico.

A cross-sectional study was carried out to estimate prevalence of child abuse with battering among patients under age 14 for alleged disciplinary purposes. The reference population were children attending pediatric out-patient services at the University Hospital in Campinas, State of São Paulo, Brazil, a city of one million inhabitants with universal coverage in terms of accessing health care in the unit under study. Interviews were carried out with 130 parents or guardians in a randomly selected group according to order of attendance, and the prevalence of child abuse was estimated at 10.8%, considering as positive cases those where parents referred child battering under age one year or where there was evidence of bodily lesion over age one year. A validation study for the experimental questionnaire is proposed in order to allow for future estimation of population prevalence or incidence. The use of qualitative methods is also recommended as a means of gathering detailed data on socio-psychological determination for the supposedly disciplinary aggression with child abuse.