Quantum Oscillations of Elastic Moduli and Softening of Phonon Modes in Metals

In this paper we present a theoretical analysis of the effect of magnetostriction on quantum oscillations of elastic constants in metals under strong magnetic fields. It is shown that at low temperatures a significant softening of some acoustic modes could occur near peaks of quantum oscillations of the electron density of states (DOS) at the Fermi surface (FS). This effect is caused by a magnetic instability of a special kind, and it can give rise to a lattice instability. We also show that the most favorable conditions for this instability to be revealed occur in metals whose Fermi surfaces include nearly cylindrical segments.Comment: 5 pages, 1 figur

Oral ibandronate for the treatment of metastatic bone disease in breast cancer: efficacy and safety results from a randomized, double-blind, placebo-controlled trial

Background: We report the first results of a randomized trial assessing a new oral aminobisphosphonate, ibandronate, in patients with bone metastases from breast cancer. Patients and methods: Patients (n = 435) received placebo, or oral ibandronate 20 mg or 50 mg once-daily for 96 weeks. The primary efficacy measure was the number of 12-week periods with new bone complications [skeletal morbidity period rate (SMPR)]. Multivariate Poisson regression analysis assessed the relative risk reduction of skeletal-related events. Secondary efficacy analyses included bone pain and analgesic use. Adverse events were monitored. Results: SMPR was significantly reduced with oral ibandronate [placebo 1.2, 20 mg group 0.97 (P = 0.024), 50 mg group 0.98 (P = 0.037)]. Ibandronate 50 mg significantly reduced the need for radiotherapy (P = 0.005 versus placebo). The relative risk of skeletal events was reduced by 38% (20 mg dose) and 39% (50 mg dose) versus placebo (P = 0.009 and P = 0.005). The tolerability profile of ibandronate was similar to placebo. Conclusions: Oral ibandronate is an effective and well-tolerated treatment for metastatic bone disease. The 50 mg dose is being further evaluated in clinical trials, and this dose was recently approved in the European Union for the prevention of skeletal events in patients with breast cancer and bone metastase

Use of case reports and the Adverse Event Reporting System in systematic reviews: overcoming barriers to assess the link between Crohn’s disease medications and hepatosplenic T-cell lymphoma

BACKGROUND: To identify demographic and clinical characteristics associated with cases of hepatosplenic T-cell lymphoma (HSTCL) in patients with Crohn’s disease, and to assess strength of evidence for a causal relationship between medications and HSTCL in Crohn’s disease. METHODS: We identified cases of HSTCL in Crohn’s disease in studies included in a comparative effectiveness review of Crohn’s disease medications, through a separate search of PubMed and Embase for published case reports, and from the Food and Drug Administration (FDA) Adverse Event Reporting System (AERS). We used three causality assessment tools to evaluate the relationship between medication exposure and HSTCL. RESULTS: We found 37 unique cases of HSTCL in patients with Crohn’s disease. Six cases were unique to the published literature and nine were unique to AERS. Cases were typically young (<40 years of age) and male (86%). The most commonly reported medications were anti-metabolites (97%) and anti-tumor necrosis factor alpha (anti-TNFa) medications (76%). Dose and duration of therapy were not consistently reported. Use of aminosalicylates and corticosteroids were rarely reported, despite the high prevalence of these medications in routine treatment. Using the causality assessment tools, it could only be determined that anti-metabolite and anti-TNFa therapies were possible causes of HSTCL in Crohn’s disease based on the data contained in the case reports. CONCLUSION: Systematic reviews that incorporate case reports of rare lethal events should search both published literature and AERS, but consideration should be given to the limitations of case reports. In this study, establishing a causative effect other than ‘possible’ between anti-metabolite or anti-TNFa therapies and HSTCL was not feasible because case reports lacked data required by the causality assessments, and because of the limited applicability of causality assessment tools for rare irreversible events. We recommend minimum reporting requirements for case reports to improve causality assessment and routine reporting of rare life-threatening events, including their absence, in clinical trials to help clinicians determine whether rare adverse events are causally related to a medication

Anisotropic Magnetoconductance in Quench-Condensed Ultrathin Beryllium Films

Near the superconductor-insulator (S-I) transition, quench-condensed ultrathin Be films show a large magnetoconductance which is highly anisotropic in the direction of the applied field. Film conductance can drop as much as seven orders of magnitude in a weak perpendicular field (< 1 T), but is insensitive to a parallel field in the same field range. We believe that this negative magnetoconductance is due to the field de-phasing of the superconducting pair wavefunction. This idea enables us to extract the finite superconducting phase coherence length in nearly superconducting films. Our data indicate that this local phase coherence persists even in highly insulating films in the vicinity of the S-I transition.Comment: 4 pages, 4 figure RevTex, Typos Correcte