Manipulation of electronic transport in the Bi(111) surface state.

We demonstrate the controlled manipulation of the 2D-electronic transport in the surface state of Bi(111) through the deposition of small amounts of Bi to generate adatoms and 2D islands as additional scatterers. The corresponding increase in resistance is recorded in situ and in real time. Model calculations based on mean-field nucleation theory reveal a constant scattering efficiency of adatoms and of small 2D Bi islands, independent of their size. This finding is supported by a detailed scanning tunneling microscopy and spectroscopy study at 5 K which shows a highly anisotropic scattering pattern surrounding each surface protrusion.

Lost in reciprocal space? Determination of the scattering condition in spot profile analysis low-energy electron diffraction.

The precise knowledge of the diffraction condition, i.e., the angle of incidence and electron energy, is crucial for the study of surface morphology through spot profile analysis low-energy electron diffraction (LEED). We demonstrate four different procedures to determine the diffraction condition: employing the distortion of the LEED pattern under large angles of incidence, the layer-by-layer growth oscillations during homoepitaxial growth, a G(S) analysis of a rough surface, and the intersection of facet rods with 3D Bragg conditions.

Quetiapine alone and added to a mood stabilizer for serious mood disorders.

BACKGROUND: Use of antipsychotic medication intermittently or over the long term may be necessary in treating patients with bipolar disorder whose symptoms have responded suboptimally to standard mood-stabilizing agents. Quetiapine fumarate is an effective novel antipsychotic with mixed serotonergic (5-HT2) and dopaminergic (D2) activity. This is an open-label, 12-week prospective study to assess the efficacy and tolerability of quetiapine in the treatment of patients with bipolar and schizoaffective disorder who were suboptimally responsive to mood stabilizers alone. METHOD: Participants in the study were inpatients or outpatients with a DSM-IV diagnosis of bipolar or schizoaffective disorder. Baseline psychopathology was evaluated with the Brief Psychiatric Rating Scale (BPRS), the Young Mania Rating Scale (YMRS), and the Hamilton Rating Scale for Depression (HAM-D). Involuntary movements were rated with the Simpson-Angus Neurologic Rating Scale. Quetiapine was added on an open-label basis and increased to optimum clinical dosage. Psychopathology and Abnormal Involuntary Movement Scale ratings were repeated weekly for the first 4 weeks and then again at weeks 8 and 12. RESULTS: Ten individuals with bipolar disorder and 10 with schizoaffective disorder received quetiapine therapy. Overall, patients improved, with significant improvement in BPRS (p < .001), YMRS (p = .043), and HAM-D scores (p = .002). Simpson-Angus score also significantly decreased (p = .02). Overall. quetiapine was well tolerated by patients in this group with serious mood disorders. The mean +/- SD quetiapine dose was 202.9 +/- 124.3 mg/day (range, 50-400 mg/day). Mean weight gain was 10.9 lb (4.9 kg). CONCLUSION: Although limited by its small size, open-label design, and relative gender homogeneity, this study suggests that quetiapine therapy may be useful in the treatment of individuals with serious mood disorders who are suboptimally responsive to mood stabilizers alone. These preliminary findings should be explored in larger, controlled trials.

Risperidone therapy in treatment refractory acute bipolar and schizoaffective mania.

This pilot study evaluated the efficacy of risperidone therapy in patients with bipolar I or schizoaffective mania who were treatment resistant or treatment intolerant. Patient psychopathology and involuntary movements were evaluated with a variety of scales, and risperidone was administered on an open-label basis. Five of six patients (all bipolar) discontinued risperidone therapy because of adverse drug effects (2 patients), lack of significant drug response and subjective clinical worsening (1 patient), or worsening of manic symptoms (2 patients). One patient with schizoaffective illness improved. Risperidone used without the addition of a mood stabilizer was ineffective in treating pure manic psychosis. In some vulnerable bipolar patients, risperidone monotherapy may have antidepressant activity that could exacerbate mania. If risperidone proves to have antidepressant activity, it may become an important agent in the therapy of patients with depressive symptoms and psychosis.