One Dimensional Kondo Lattice Model Studied by the Density Matrix Renormalization Group Method

Recent developments of the theoretical investigations on the one-dimensional Kondo lattice model by using the density matrix renormalization group (DMRG) method are discussed in this review. Short summaries are given for the zero-temperature DMRG, the finite-temperature DMRG, and also its application to dynamic quantities. Away from half-filling, the paramagnetic metallic state is shown to be a Tomonaga-Luttinger liquid with the large Fermi surface. For the large Fermi surface its size is determined by the sum of the densities of the conduction electrons and the localized spins. The correlation exponent K_rho of this metallic phase is smaller than 1/2. At half-filling the ground state is insulating. Excitation gaps are different depending on channels, the spin gap, the charge gap and the quasiparticle gap. Temperature dependence of the spin and charge susceptibilities and specific heat are discussed. Particularly interesting is the temperature dependence of various excitation spectra, which show unusual properties of the Kondo insulators.Comment: 18 pages, 23 Postscript figures, REVTe

Supershells in Metal Clusters: Self-Consistent Calculations and their Semiclassical Interpretation

To understand the electronic shell- and supershell-structure in large metal clusters we have performed self-consistent calculations in the homogeneous, spherical jellium model for a variety of different materials. A scaling analysis of the results reveals a surprisingly simple dependence of the supershells on the jellium density. It is shown how this can be understood in the framework of a periodic-orbit-expansion by analytically extending the well-known semiclassical treatment of a spherical cavity to more realistic potentials.Comment: 4 pages, revtex, 3 eps figures included, for additional information see http://radix2.mpi-stuttgart.mpg.de/koch/Diss

Classical Analysis of Phenomenological Potentials for Metallic Clusters

The classical trajectories of single particle motion in a Wodds-Saxon and a modified Nilsson potential are studied for axial quadrupole deformation. Both cases give rise to chaotic behaviour when the deformation in the Woods-Saxon and the l**2 term in the modified Nilsson potential are turned on. Important similarities, in particular with regard to the shortest periodic orbits, have been found.Comment: 9 pages LaTex + 4 figures available via e-mail requests from the authors, to appear in Phys.Rev.Let

Periodic orbit theory for realistic cluster potentials: The leptodermous expansion

The formation of supershells observed in large metal clusters can be qualitatively understood from a periodic-orbit-expansion for a spherical cavity. To describe the changes in the supershell structure for different materials, one has, however, to go beyond that simple model. We show how periodic-orbit-expansions for realistic cluster potentials can be derived by expanding only the classical radial action around the limiting case of a spherical potential well. We give analytical results for the leptodermous expansion of Woods-Saxon potentials and show that it describes the shift of the supershells as the surface of a cluster potential gets softer. As a byproduct of our work, we find that the electronic shell and supershell structure is not affected by a lattice contraction, which might be present in small clusters.Comment: 15 pages RevTex, 11 eps figures, additional information at http://www.mpi-stuttgart.mpg.de/docs/ANDERSEN/users/koch/Diss

Intracapsular tonsillectomy in the treatment of recurrent and chronic tonsillitis in adults : a protocol of a prospective, single-blinded, randomised study with a 5-year follow-up (the FINITE trial)

Introduction The standard surgical treatment for recurrent or chronic tonsillitis is extracapsular tonsillectomy. Recent studies show that intracapsular tonsillectomy has the potential to reduce the postoperative morbidity of patients undergoing tonsil surgery. The Finnish Intracapsular Tonsillectomy (FINITE) trial aims to provide level I evidence to support the hypothesis that the recovery time from tonsil surgery can be reduced with intracapsular tonsillectomy. Additionally, from this trial, major benefits in quality of life, reduction of postoperative complications, treatment costs and throat symptoms might be gained. Methods and analysis The FINITE trial is a prospective, randomised, controlled, patient-blinded, three-arm clinical trial. It is designed to compare three different surgical methods being extracapsular monopolar tonsillectomy versus intracapsular microdebrider tonsillectomy versus intracapsular coblation tonsillectomy in the treatment of adult patients (16-65 years) suffering from recurrent or chronic tonsillitis. The study started in September 2019, and patients will be enrolled until a maximum of 200 patients are randomised. Currently, we are in the middle of the study with 125 patients enrolled as of 28 February 2022 and data collection is scheduled to be completed totally by December 2027. The primary endpoint of the study will be the recovery time from surgery. Secondary endpoints will be the postoperative pain scores and the use of analgesics during the first 3 weeks of recovery, postoperative haemorrhage, quality of life, tonsillar remnants, need for revision surgery, throat symptoms, treatment costs and sick leave. A follow-up by a questionnaire at 1-21 days and at 1, 6, 24 and 60 months will be conducted with a follow-up visit at the 6-month time point. Ethics and dissemination Ethical approval was obtained from the Medical Ethics Committee of the Hospital District of Southwest Finland (reference number 29/1801/2019). Results will be made publicly available in peer-reviewed scientific journals.Peer reviewe

Rough droplet model for spherical metal clusters

We study the thermally activated oscillations, or capillary waves, of a neutral metal cluster within the liquid drop model. These deformations correspond to a surface roughness which we characterize by a single parameter $\Delta$. We derive a simple analytic approximate expression determining $\Delta$ as a function of temperature and cluster size. We then estimate the induced effects on shell structure by means of a periodic orbit analysis and compare with recent data for shell energy of sodium clusters in the size range $50 < N < 250$. A small surface roughness $\Delta\simeq 0.6$ \AA~ is seen to give a reasonable account of the decrease of amplitude of the shell structure observed in experiment. Moreover -- contrary to usual Jahn-Teller type of deformations -- roughness correctly reproduces the shape of the shell energy in the domain of sizes considered in experiment.Comment: 20 pages, 4 figures, important modifications of the presentation, to appear in Phys. Rev.

Orbits in Large Aluminum Clusters: Five-Pointed Stars

The distinctions in the mass spectra of large sodium (Na_N) and aluminum (Al_N) clusters are discussed. A semiclassical method is used to describe the shell effects within a spherical jellium model. It allows one to analyze the relative role of different classical trajectories in the formation of electronic supershells in clusters of various sizes at zero and finite temperatures. A criterion for the hardness of the self-consistent potential is formulated. The conjecture that the five-point-star trajectories make the main contribution to the spectral oscillations for large soft-potential Al_N (250<N<900) clusters is substantiated. The computational results are in agreement with the mass spectra of the Al_N clusters at T ~ 300 K.Comment: 5 pages, 3 figures, PDF forma

Phenotypic Analysis of Disease-Relevant T Cells in Dermatitis Herpetiformis

publishedVersionNon peer reviewe

Mutation analysis of the ATR gene in breast and ovarian cancer families

INTRODUCTION: Mutations in BRCA1, BRCA2, ATM, TP53, CHK2 and PTEN account for only 20–30% of the familial aggregation of breast cancer, which suggests the involvement of additional susceptibility genes. The ATR (ataxia-telangiectasia- and Rad3-related) kinase is essential for the maintenance of genomic integrity. It functions both in parallel and cooperatively with ATM, but whereas ATM is primarily activated by DNA double-strand breaks induced by ionizing radiation, ATR has been shown to respond to a much broader range of DNA damage. Upon activation, ATR phosphorylates several important tumor suppressors, including p53, BRCA1 and CHK1. Based on its central function in the DNA damage response, ATR is a plausible candidate gene for susceptibility to cancer. METHODS: We screened the entire coding region of the ATR gene for mutations in affected index cases from 126 Finnish families with breast and/or ovarian cancer, 75 of which were classified as high-risk and 51 as moderate-risk families, by using conformation sensitive gel electrophoresis and direct sequencing. RESULTS: A large number of novel sequence variants were identified, four of which – Glu254Gly, Ser1142Gly, IVS24-48G>A and IVS26+15C>T – were absent from the tested control individuals (n = 300). However, the segregation of these mutations with the cancer phenotype could not be confirmed, partly because of the lack of suitable DNA samples. CONCLUSION: The present study does not support a major role for ATR mutations in hereditary susceptibility to breast and ovarian cancer