Indications and candidacy for active middle ear implants

Currently, there are two active middle ear implants available commercially: the Vibrant Soundbridge system and the Carina system. A third active middle ear implant, the Esteem, is under clinical evaluation. All devices are indicated for patients with moderate-to-severe hearing loss. Because active middle ear implants are directly coupled to middle ear structures, many of the problems that patients with conventional hearing aids report, such as acoustic feedback, occlusion, and irritation of the outer ear canal, are avoided. In addition, AMEI patients perform well in background noise. However, indications for AMEIs are selective and candidates should be carefully evaluated before surgery. Before considering an AMEI, patients should be provided with conventional hearing aids. Only when benefit is insufficient and audiological selection criteria are met is further candidacy evaluation indicated. Since Colletti described coupling the Vibrant Soundbridge directly onto the round window membrane in 2006, the indications for the Vibrant Soundbridge have expanded and the VSB is implanted in patients with conductive and mixed hearing losses. Patients have often undergone middle ear surgery before. Especially mixed hearing loss cases with 30-60 dB HL sensorineural hearing impairment and 30-40 dB HL air-bone gaps may be helped by this new application.

Electron correlation beyond the local density approximation: self-interaction correction in gadolinium

We report on detailed first-principles calculations which focus on the magnetic and structural properties of the (0001) surface of gadolinium. The electronic correlation within the localized 4f states is treated within the self-interaction correction (SIC), thus going beyond the local spin-density approximation. The ferromagnetic ground state is predicted correctly if the SIC is applied; the effect of surface relaxations on Heisenberg exchange parameters and on the Curie temperature are addressed by Monte Carlo calculations. The SIC also has a profound effect on the dispersion of the d surface states, due to hybridization of the 4f states with the 5d valence states. The best agreement with photoemission experiments is obtained within the transition state approximation, which takes into account the orbital relaxation. The Rashba spin-orbit coupling in the d surface states is fully captured by our relativistic multiple scattering approach.

Tailoring magnetic interlayer coupling in La0.7Sr0.3MnO3/SrRuO3 superlattices

The magnetic interlayer coupling in La0.7Sr0.3MnO3/SrRuO3 superlattices was investigated. High quality superlattices with ultrathin La0.7Sr0.3MnO3 and SrRuO3 layers were fabricated by pulsed laser deposition. The superlattices grew coherently with Mn/Ru intermixing restricted to about one interfacial monolayer. Strong antiferromagnetic interlayer coupling depended delicately on magnetocrystalline anisotropy and intermixing at interfaces. Ab initio calculations elucidated that the antiferromagnetic coupling is mediated by the Mn-O-Ru bond. The theoretical calculations allowed for a quantitative correlation between the total magnetic moment of the superlattice and the degree of Mn/Ru intermixing.

Silicon surface with giant spin splitting

We demonstrate a giant Rashba-type spin splitting on a semiconducting substrate by means of a Bi-trimer adlayer on a Si(111) wafer. The in-plane inversion symmetry is broken inducing a giant spin splitting with a Rashba energy of about 140 meV, much larger than what has previously been reported for any semiconductor heterostructure. The separation of the electronic states is larger than their lifetime broadening, which has been directly observed with angular resolved photoemission spectroscopy. The experimental results are confirmed by relativistic first-principles calculations.

Telomerase activity determined by conventional telomeric repeat amplification protocol and reverse transcriptase‐polymerase chain reaction assay in ovarian lesions: A comparison of assays

OBJECTIVE

Telomerase is capable of restoring telomeric sequence lost during replication. No or low levels of telomerase activity are present in normal somatic cells, whereas up to 85-90% of all cancer cells express telomerase activity, suggesting telomerase as a possible tumor marker. The catalytic subunit, hTERT, correlates with the activity of the enzyme.

MATERIAL AND METHODS

Telomerase activity in ovarian tissue was measured by the functional telomeric repeat amplification protocol (TRAP)eze assay, and a quantitative reverse-transcriptase-polymerase chain reaction (RT-PCR) assay measuring the expression of the telomerase catalytic subunit, hTERT.

RESULTS

A weakly positive correlation was found between telomerase activity and severity of ovarian disease using the results of the TRAP assay, compared to a strongly positive correlation considering the results obtained in the RT-PCR assay. A statistically significant difference between the benign and borderline groups was present using the RT-PCR assay, allowing for screening for both borderline and primary malignant conditions with a specificity of 97% and a sensitivity of 68%. No significant statistical difference was found between telomerase activity in benign and borderline conditions when using the TRAP assay. When screening for primary malignancy, the specificity and sensitivity rates were 94% and 21%, respectively.

CONCLUSIONS

The RT-PCR assay allowed discrimination between benign and borderline and malignant cases, and thereby proved superior to the TRAP assay, which could not discriminate the benign cases from the borderline cases. This suggests that the RT-PCR assay may be useful in screening for both borderline and primary malignancy in ovarian lesions.

Magnetic anisotropy and magnetization dynamics of individual atoms and clusters of Fe and Co on Pt(111)

The recently discovered giant magnetic anisotropy of single magnetic Co atoms raises the hope of magnetic storage in small clusters. We present a joint experimental and theoretical study of the magnetic anisotropy and the spin dynamics of Fe and Co atoms, dimers, and trimers on Pt(111). Giant anisotropies of individual atoms and clusters as well as lifetimes of the excited states were determined with inelastic scanning tunneling spectroscopy. The short lifetimes due to hybridization-induced electron-electron scattering oppose the magnetic stability provided by the magnetic anisotropies.

[Cochlear implants in isolated temporal bones: evaluation of electrode position with 64-slice computed tomography]

BACKGROUND

For the functional outcome after cochlear implant surgery, the electrode position is of essential importance. Therefore, radiological techniques to localize the electrode within the cochlea are becoming increasingly important. In our study, we used multi-slice computed tomography (CT) to find radiological criteria to allocate the electrode within the cochlea.

METHODS

Ten Nucleus 24 RCA electrodes were implanted into isolated human temporal bones using an extended cochleostomy and the Advance Off-Stylet technique. Five electrodes were implanted into the scala tympani and five into the scala vestibuli. After implantation, the temporal bones were blinded to the radiologist, and 64-slice CT scans were performed and analysed.

RESULTS AND CONCLUSIONS

In all 10 cases, the surgical positioning of the electrode was equal to the radiological analysis of the CT scans. Radiological criteria were found that permit correct identification of the electrode within the cochlea. We think that this technique is sufficient for most questions concerning quality control and is widely available.

Ultrasound-guided transbronchial biopsy of solitary pulmonary nodules less than 20 mm

Transbronchial biopsy of solitary pulmonary nodules (SPNs) is usually performed under fluoroscopic guidance, but success varies widely. Endobronchial ultrasonography (EBUS) may increase the likelihood of success. The ability of EBUS-guided transbronchial biopsy to sample SPNs of <20 mm in diameter was assessed. All patients seen between June 2004 and August 2007 in whom computed tomography identified a SPN of <20 mm underwent bronchoscopic general anaesthesia or moderate sedation for a radial EBUS-guided examination. If a typical ultrasonographic picture of solid tissue could be identified, specimens were taken through a catheter with forceps. If the node was not detected within 20 min, the procedure was terminated. Of 100 nodules detected in 100 consecutive patients, 67 (mean diameter 15 mm) were visualised using EBUS and biopsy specimens taken. A diagnosis was established for 46 (46%) patients. If the lesion was visualised by EBUS, the diagnostic success was 69% (46 out of 67). The 33 patients whose nodules could not be sampled underwent surgical biopsy. Pneumothorax occurred in three patients. For SPNs of <20 mm that can be detected using ultrasound, EBUS-guided transbronchial biopsy is safe and effective.

Myositis associated with localized lipodystrophy: an unrecognized condition?

Lipodystrophies represent a heterogeneous group of diseases characterized by altered body fat repartition and often metabolic alterations. Here we illustrate a 20 year old male with myositis in association with localized lipodystrophy. Immunohistochemical stainings revealed a regular pattern of dystrophin, dysferlin, sarcoglycans, and theletonin. Furtermore, there was no evidence of Lamin A/C deficiency. A nearly identical clinical and histological picture has been described in three patients up to now. Although it is difficult to speculate on a causative pathophysiological mechanism at this time, it is possible that this association represents an unrecognized condition.

Wurtzite-type CoO nanocrystals in ultrathin ZnCoO films

Surface x-ray diffraction experiments reveal that, in cobalt-doped ZnO films two to five monolayers thick, Wurtzite-type CoO nanocrystals are coherently embedded within a hexagonal boron-nitride- (h-BN)-type ZnO matrix, supporting the model of a phase separation. First-principles calculations confirm that, in contrast with ZnO, the formation of h-BN-type CoO is unfavorable in the ultrathin film limit. Our results are important for understanding magnetic properties of transition metal-doped semiconductors in general.