Tilting structures in inverse perovskites, M3TtO (M = Ca, Sr, Ba, Eu; Tt = Si, Ge, Sn, Pb).

Single-crystal X-ray diffraction experiments were performed for a series of inverse perovskites, M3TtO (M = Ca, Sr, Ba, Eu; Tt = tetrel element: Si, Ge, Sn, Pb) in the temperature range 500-50 K. For Tt = Sn, Pb, they crystallize as an 'ideal' perovskite-type structure (Pm3m, cP5); however, all of them show distinct anisotropies of the displacement ellipsoids of the M atoms at room temperature. This behavior vanishes on cooling for M = Ca, Sr, Eu, and the structures can be regarded as `ideal' cubic perovskites at 50 K.

Challenge of magnetism in strongly correlated open-shell 2p systems.

We report on theoretical investigations of the exotic magnetism in rubidium sesquioxide Rb4O6, a model correlated system with an open 2p shell. Experimental investigations indicated that Rb4O6 is a magnetically frustrated insulator. The frustration is explained here by electronic structure calculations that incorporate the correlation between the oxygen 2p electrons and deal with the mixed-valent oxygen.

Magnetic resonance imaging of the femoral trochlea: evaluation of anatomical landmarks and grading articular cartilage in cadaveric knees.

Purpose: The purpose of the study was to define magnetic resonance imaging (MRI) findings before and after contrast medium opacification of the knee joint in cadaveric specimens to demonstrate anatomical landmarks of the trochlear surface in relation to the neighboring structures, and to evaluate different MRI sequences in the detection of cartilage defects of the trochlear and patellar surface of the knee.

Materials And Methods: The morphology and relationship of the proximal trochlear surface to the prefemoral fat of the distal femur were investigated by use of different MR sequences before and after intra-articular gadolinium administration into the knee joint in ten cadaveric knees. Anatomic sections were subsequently obtained.

Microscopic access to long-range diffusion parameters of the fast lithium ion conductor Li7BiO6 by solid state 7Li stimulated echo NMR.

Li self-diffusion in rhombohedral Li7BiO6, being a promising basic material for cathodes of rechargeable ion batteries, is studied by means of 7Li stimulated echo NMR. Using the pulse sequence introduced by Jeener and Broekaert, a spin-alignment echo is created whose amplitude decay is recorded as a function of mixing time. The so-obtained two-time correlation functions follow stretched exponential behavior and lead to decay rates which can be identified directly with microscopic Li motional correlation rates (tau(-1)).

Value of fat-suppressed PD-weighted TSE-sequences for detection of anterior and posterior cruciate ligament lesions--comparison to arthroscopy.

Objective: To evaluate fat-suppressed (FS) proton-density-weighted (PDw) turbo spin-echo (TSE) magnetic resonance imaging for the detection of anterior and posterior cruciate ligament lesions in comparison to arthroscopy.

Materials And Methods: In a prospective study 31 knee joints were imaged on a 1.5T MR scanner (Vision, Siemens, Erlangen) prior to arthroscopy using following sequences: (a) sagittal FS-PDw/T2w TSE (TR/TE: 4009/15/105 ms); (b) sagittal PDw/T2w TSE (TR/TE:3800/15/105 ms).

CT-guided lymphoscintigraphy in patients with squamous cell carcinoma of the head and neck: a feasibility study.

Accurate knowledge of lymphatic drainage facilitates planning of surgery for patients with squamous cell carcinoma of the head and neck. The aim of this study was to evaluate the feasibility of a new injection technique for lymph node detection in patients with squamous cell carcinoma of the hypopharynx and larynx, in whom simple peritumoural injection is hampered by the tumour localisation. Computed tomography (CT)-guided lymphoscintigraphy was performed in a total of 13 patients with squamous cell carcinoma of the hypopharynx and larynx who could not be injected by simple visual inspection.

Myeloprotective effects of different amifostine regimens in rabbits undergoing high-dose treatment with 186rhenium-(tin)1,1- hydroxyethylidene diphosphonate (186Re-HEDP).

The aim of this study is to investigate the myeloprotective effects of different amifostine regimens in rabbits undergoing high-dose treatment with 186Rhenium-(tin)1,1-hydroxyethylidene diphosphonate (186Re-HEDP) and to analyze the impact of amifostine on the bone uptake of the radiopharmaceutical. All animals were treated with 1000 MBq 186Re-HEDP. Group ReA received 500 mg amifostine prior to radionuclide therapy, group ReA3 received 3 x 200 mg amifostine 24 hours and 30 minutes prior to and 24 hours after radionuclide therapy.

New insights into the structural and dynamical features of lithium hexaoxometalates Li7MO6 (M = Nb, Ta, Sb, Bi).

We present a (re)investigation of the hexaoxometalates Li(8)MO(6) (M = Sn, Pb, Zr, Hf) and Li(7)MO(6) (M = Nb, Ta, Sb, Bi). Lithium motion and ionic conductivity in the hexaoxometalates were studied using impedance spectroscopy (for Li(7)MO(6), M = Sb, Bi, Ta) and (6)Li and (7)Li solid-state nuclear magnetic resonance (for Li(7)TaO(6)). The NMR data indicate a considerable exchange of Li among the tetrahedral and octahedral voids even at ambient temperature.

Adhesive capsulitis of the shoulder: diagnosis using magnetic resonance arthrography, with arthroscopic findings as the standard.

Objective: The purpose of this study was to assess the usefulness of magnetic resonance (MR) arthrography of the glenohumeral joint in the diagnosis of adhesive capsulitis.

Methods: MR arthrography of the glenohumeral joint was performed in 16 patients with arthroscopically proven adhesive capsulitis and 11 controls. Thickness of the joint capsule and synovium, filling ratio of the fluid-distended axillary recess to the posterior joint cavity, and a width of the rotator cuff interval were measured by 2 musculoskeletal radiologists.

Influence of thrombus age on the mechanical thrombectomy efficacy of the amplatz thrombectomy device in vitro.

Purpose: To determine the efficacy of thrombectomy for the Amplatz Thrombectomy Device (ATD) according to the age of the thrombus.

Methods: Thrombectomy was performed with the 7 Fr or 8 Fr ATD. Five-day-old or 8-day-old thrombi were made from porcine blood by clotting within silicone tubes to be used in a flow model.

Bone uptake studies in rabbits before and after high-dose treatment with 153Sm-EDTMP or 186Re-HEDP.

Unlabelled: The aim of this animal study was to measure the bone uptake of (99m)Tc-hydroxymethylene diphosphonate (HDP) before and after high-dose treatment with (153)Sm-ethylenediaminetetramethylenephosphonate (EDTMP) or (186)Re-(tin)1,1-hydroxyethylidene diphosphonate (HEDP) to prove or disprove post-therapeutic alterations of bone uptake of radiolabeled bisphosphonates.

Methods: Quantitative bone scanning using 100 MBq (99m)Tc-HDP was performed on 12 rabbits before and 8 wk after radionuclide therapy with 1,000 MBq of either (153)Sm-EDTMP or (186)Re-HEDP. Whole-body images were acquired at 3 min, 3 h, and 24 h after injection, and the activities for the whole body, urinary bladder, and soft tissue were measured by region-of-interest technique.

MR imaging of the neural foramina of the cervical spine. Comparison of 3D-DESS and 3D-FISP sequences.

Purpose: To assess whether a single three-dimensional double-echo steady state (3D-DESS) sequence can produce equivalent results when compared to a 3D free induction with steady precession (3D-FISP) sequence for the evaluation of the neural foraminal diameter and structures.

Material And Methods: Five phantoms were imaged on CT with 3-mm axial slices followed by reformatted axial 3D-DESS and 3D-FISP sequences. In addition, 3D-DESS and 3D-FISP sequences of 20 healthy subjects were compared with regard to image quality, differentiation between vertebrae and discs, differentiation between discs and neural foramina, and differentiation between vertebrae and neural foramina.