A Transport Analysis of the BEEM Spectroscopy of Au/Si Schottky Barriers

A systematic transport study of the ballistic electron emission microscopy (BEEM) of Au/Si(100) and Au/Si(111) Schottky barriers for different thicknesses of the metal layer and different temperatures is presented. It is shown that the existing experimental data are compatible with a recently predicted bandstructure-induced non-forward electron propagation through the Au(111) layer.Comment: 5 pages, Latex-APS, 1 postscript figure, http://www.icmm.csic.es/Pandres/pedro.htm. Phys. Stat. Sol. (b) (to appear), HCIS-10 Conf, Berlin 199

Is radiographic measurement of distal femoral torsion reliable?

BACKGROUND: Distal femur torsion (DFT) is a crucial parameter in knee replacement surgery. The reference standard for measuring DFT is posterior condylar angle (PCA) measurement using computed tomography (CT). The objective of this study was to assess the feasibility and reliability of a radiographic PCA measurement method. MATERIALS AND METHODS: We studied 125 osteoarthritic knees in 79 patients (42 women and 37 men) with a mean age of 71.6 ± 8.8 years (range 47 to 86 years); 32 knees were aligned, 85 in varus, and eight in valgus. DFT was measured on an antero-posterior (AP) radiograph of the knee in 90° of flexion (known as the seated AP view). The PCA was defined as the angle subtended by the tangent to the posterior condyles and the transepicondylar axis (anatomic PCA [aPCA]) or the line connecting the lateral epicondyle to the medial sulcus (surgical PCA [sPCA]). The PCA was conventionally recorded as positive in the event of external torsion and negative in the event of internal torsion. PCA measurements were performed three times by each of five observers to allow assessments of inter-observer and test-retest reliabilities. RESULTS: aPCA was consistently negative (mean, -6.1 ± 1.6°) (range, 0 to -10°); inter-observer and test-retest reliability were satisfactory (0.54 CONCLUSION: Radiographic measurement of DFT is simple and non-invasive. Measurement reproducibility was satisfactory for aPCA but not for sPCA. aPCA showed marked inter-individual variability and tended to increase when the knee was in valgus. Mean aPCA values were comparable to those reported using CT. In contrast to CT, radiographic DFT measurement can easily be incorporated into the pre- and postoperative work-ups for knee replacement surgery, provided the patient can achieve 90° of knee flexion. LEVEL OF EVIDENCE: Level IV, prospective cohort study

Isolated interfragmentary compression for nonunion of humeral shaft fractures initially treated by nailing: A preliminary report of seven cases

Introduction Plating with bone grafting is considered the gold standard treatment for nonunion of humeral shaft fractures. However, this complex procedure involves multiple risks. The aim of this study is to evaluate an alternative treatment using isolated axial interfragmentary compression for the dynamisation of humeral shaft nonunion after retrograde locked nailing. Materials and methods Between January 2000 and May 2009, 124 humeral shaft fractures were treated in our trauma department with retrograde locked nailing using the unreamed humeral nail (UHN®, Synthes, Paoli, PA, USA). Nonunion occurred in seven patients (5.6%) – five females and two males, mean age 44 years (range: 17–73 years). The nonunion was treated by applying isolated secondary interfragmentary compression. Mean follow-up was 43 months (range: 8–74 months). The Rommens score and the disabilities of the arm, shoulder and hand (DASH) score were used to evaluate the global functioning of the upper limb. Results The compression procedure was successful in all seven cases. In each case, the union occurred without any complications in 3–5 months. The mean DASH score was 25/100 (range: 8.3–60.8/100). The Rommens score was judged excellent for five of the seven patients but two were rated moderate. One of these suffered from complex regional pain syndrome type II since the fracture, and another developed a stiff shoulder 6 months after trauma. Conclusion Isolated secondary interfragmentary compression appears to be a simple and successful procedure in cases of humeral nonunion

Intérêt d’une formation théorique des internes de gynécologie obstétrique à la mesure échographique du col utérin.

National audienceOBJECTIVES:Evaluate an educational program based on "CLEAR" (Cervical Length Education and Review) in the teaching of measuring sonographic cervical length to residents in gynecology and obstetrics. METHODS:This is a prospective cohort study in a tertiary care center between May and November 2017. The residents were asked to collect 5 cervical length images from patients suspected with threatened preterm labor. A theoretical session on cervix measurement image criteria based on "CLEAR" program was taught to all residents. Then, they had to collect 5 new cervical length images. All the images were reviewed by two experienced reviewers, blinded to the resident and whether the image was obtained before or after the theoretical session and based on 8 criteria. RESULTS:Ten residents participated to the study. The mean total score CLEAR was significantly higher post-intervention: 6.6±0.9 vs. 4.3±2.1, positive difference of 2.3±2.3 (P<0.001). Improvement was most significant with the junior residents: 3.6 pre vs. 6.5 post-intervention. CONCLUSION:Educational program based on CLEAR criteria allowed to improve the competence of residents in measuring sonographic cervical length, although this can also be correlated with the progression of residents during the semester. It could be implemented systematically with the aim of CLEAR certification to standardize the teaching of residents in gynecology and obstetrics

Birefringence in Polarization Insensitive Semiconductor-Optical Amplifiers: Influence on Four-Wave Mixing

Birefringence in polarization insensitive semiconductor-optical amplifiers is investigated by four-wave mixing. Experimental and theoretical data for detunings up to 6 THz are presented

Time-resolved relaxation oscillations in gain-clamped semiconductor optical amplifiers by pump and probe measurements

Pump and probe measurements with femtosecond resolution are performed on a gain-clamped semiconductor optical amplifier, a structure that contains a lasing mode. The corresponding relaxation oscillations are observed in the temporal gain recovery of the amplifier. The current dependence of the oscillations is well reproduced by a small-signal analysis of the laser rate equations. The gain recovery can be very fast, we measure damping rates of up to 40 GHz