A general formalism for diagonalizing quadratic forms of boson operators [7], is used to obtain a translationally invariant variational ansatz which is suitable for calculating the polaron self-energy, effective mass, and energy momentum relation in both coupling limits. The self-energy and effective mass are calculated in the weak-coupling limit. The strong coupling limit shows the wellknown &dependence of the self-energy. Diagonalizing the quadratic part of the recoil term gives rise to an additional self-energy contribution to the cutoff.Ein allgemeiner Formalismus zur Diagonalisierung quadratischer Formen von Boson-Operatoren [7] bildet die Grundlage fur einen translationsinvarianten Variationsansatz, der zur Berechnung der Selbstenergie, der effektiven Masse und der Energie-Impuls-Relation des Polarons in den Grenzfallen schwacher und starker Kopplung dienen kann. Fur schwache Kopplung werden Selbstenergie und effektive Masse berechnet und fur starke Kopplung die a2-Abhangigkeit der Selbstenergie bestatigt. Die Diagonalisierung der quadratischen Anteile des RuckstoBterms fiihrt auf einen zuslltzlichen Beitrag des Cut-off zur Selbstenergie.

AimThis study was designed to evaluate the performance of shear-wave elastography as a diagnostic tool for prostate cancer in a larger cohort of patients than previously reported.Patients and methodsSeventy-three patients with suspected prostate carcinoma were investigated by ultrasound elastography followed by directed biopsy. The elastographic and histological results for all biopsies were compared.ResultsAfter exclusion of invalid and non-assessable results, 794 samples were obtained for which both a histological assessment and an elastometric result (tissue stiffness in kPa) were available: according to the histology 589 were benign and 205 were malignant. Tissue elasticity was found to be weakly correlated with patient's age, PSA level and gland volume. ROC analysis showed that, for the set of results acquired, elastometry did not fulfil literature claims that it could identify malignant neoplasia with high sensitivity and specificity. However, it did show promise in distinguishing between Gleason scores ≤6 and >6 when malignancy had already been identified. Unexpected observations were the finding of a smaller proportion of tumours in the lateral regions of the prostate than generally expected, and also the observation that the elasticity of benign prostate tissue is region-sensitive, the tissue being stiffest in the basal region and more elastic at the apex.ConclusionsShear-wave elastography was found to be a poor predictor of malignancy, but for malignant lesions an elasticity cut-off of 80 kPa allowed a fairly reliable distinction between lesions with Gleason ≤6 and those with Gleason >6. We demonstrate an increase in elasticity of benign prostate tissue from the basal to the apical region.

This porcine IRE study reveals a multifocal renal ablation, while protecting surrounded renal parenchyma and collecting system over a mid-term period. That offers prevention of renal function ablating centrally located or multifocal renal masses.

SummaryBackgroundIrreversible electroporation (IRE) as newer ablation modality has been introduced and its clinical niche is under investigation. At present just one IRE system has been approved for clinical use and is currently commercially available (NanoKnife® system). In 2014, the International Working Group on Image-Guided Tumor Ablation updated the recommendation about standardization of terms and reporting criteria for image-guided tumor ablation. The IRE method is not covered in detail. But the non-thermal IRE method and the NanoKnife System differ fundamentally from established ablations techniques, especially thermal approaches, e.g. radio frequency ablation (RFA).Material/MethodsAs numerous publications on IRE with varying terminology exist so far – with numbers continuously increasing – standardized terms and reporting criteria of IRE are needed urgently. The use of standardized terminology may then allow for a better inter-study comparison of the methodology applied as well as results achieved.ResultsThus, the main objective of this document is to supplement the updated recommendation for image-guided tumor ablation by outlining a standardized set of terminology for the IRE procedure with the NanoKnife Sytem as well as address essential clinical and technical informations that should be provided when reporting on IRE tumor ablation.ConclusionsWe emphasize that the usage of all above recommended reporting criteria and terms can make IRE ablation reports comparable and provide treatment transparency to assess the current value of IRE and provide further development.

The effect of both the complexity of the two upper valence bands as well as the electron-hole exchange interaction on the exciton binding energies in wurtzite-type semiconductors is studied. The energy level scheme and explicit expressions for the lowest exciton states of both A and B series are given. Using recent very accurate experimental data on exciton energies in CdS, the averaged B band hole mass is estimated to 1.6m0, and the position of the n = 1 B(r,) exciton level to about 0.2 meV below the transverse B(r,) level. The longitudinal-transverse splitting of r5 excitons is calculated from a microscopic approach in excellent agreement with experimental data taking into account an interband momentum matrix element P& = 21 eV screened by a background dielectric constant E' = 8. The exchange parameters introduced by Cho are determined for CdS to 3j0 N 1 meV and 9j, = 2.1 meV.Es wird der EinfluS sowohl der komplexen Bandstruktur der beiden oberen Valenzbander als auch der Elektron-Loch-Austauschwechselwirkung auf die Exzitonenbindungsenergie in Wurtzit-Halbleitern untersucht. Das Energieniveauschema und explizite Ausdriicke fur die Grundzustande der A-und B-Exzitonen werden angegeben. Unter Verwendung von neueren sehr genauen experimentellen Werten der Exzitonenenergie in CdS werden die gemittelte B-Band-Lochmasse zu 1,6m0 und die Lage des n = 1 B(r?)-Exzitonenniveaus zu 0,2 meV unter dem transversalen B(I',)-Niveau bestimmt. Die Longitudinal-Transversal-Aufspaltung der r,-Exzitonen wird im Rahmsn einer mikroskopischen Theorie in sehr guter ubereinstimmung mit experimentellen Werten bestimmt, wobei das Interband-Impuls-Matrixelement P& = 21 eV mit einer ,,background"-Dielektrizitatskonstante E' = 8 abgeschirmt wird. Die von Cho eingefiihrten Austauschparameter ergeben sich fur CdS zu 3j0 = 1 meV und 9j, = 2,l meV. l) Now a t : Sektion Wissenschaftstheorie und -organisation der Humboldt-Universitat zu Berlin, Bereich Wissenschaftsgeschichte.