Search results for "Metas"

On the Nature of the Plateau in Two-Step Dinuclear Spin-Crossover Complexes

2004

A remarkable feature of the spin-crossover process in several dinuclear iron(II) compounds is a plateau in the two-step transition curve. Up to now, it has not been possible to analyse the spin state of dinuclear pairs that constitute such a plateau, due to the relative high temperatures at which the transition takes place in complexes investigated so far. We solved this problem by experimentally studying a novel dinuclear spin-crossover compound [[Fe(phdia)(NCS)(2)](2)(phdia)] (phdia: 4,7-phenanthroline-5,6-diamine). We report here on the synthesis and characterisation of this system, which exhibits a two-step spin transition at T(c1)=108 K and T(c2)=80 K, displaying 2 K and 7 K wide therm…

Lifetime of the metastable 6P 3/2 level of PbII

1989

Pb+-ions were stored in a r.f.-quadrupole trap. Short laser pulses at a 710-nm M1-transition excited the ions to the metastable 6P 3/2 level. Time-resolved registration of the subsequent decay photons at the same wavelength directly gives the lifetime of that state. No dependence of the decay rate on the density of different buffer gases up to 10−5 mbar pressure was observed and from this we deduced upper limits to the quenching cross section. We have observed, however, a small dependence on the stored ion number. The final result for the lifetime is 41.2 ± 0.7 ms in agreement with the result of a previous calculation.

Magnetic octupole moment of Yb-173 using collinear laser spectroscopy

2021

The hyperfine constants of the $4{f}^{14}6s6p^{3}P_{2}^{o}$ state in neutral Yb have been measured using three different dipole transitions. This state was recently shown to have a comparatively large hyperfine magnetic octupole splitting, and thus a puzzlingly large magnetic octupole moment. The measurement is performed using collinear laser spectroscopy on a fast atomic beam, which provides a straightforward route to probing long-lived metastable atomic states with high resolution. From the combined analysis of all three lines we find no significant evidence for a nonzero octupole moment in $^{173}\mathrm{Yb}$.

Management of Spinal Bone Metastases With Radiofrequency Ablation, Vertebral Reinforcement and Transpedicular Fixation: A Retrospective Single-Center…

2022

Spine is a frequent site of bone metastases, with a 8.5 months median survival time after diagnosis. In most cases treatment is only palliative. Several advanced techniques can ensure a better Quality of Life (QoL) and increase life expectancy. Radiofrequency ablation (RFA) uses alternating current to produce local heating and necrosis of the spinal lesion, preserving the healthy bone. RFA is supported by vertebral reinforcement through kyphoplasty and vertebroplasty in order to stabilize the fracture with polymethylmethacrylate (PMMA) injection, restoring vertebral body height and reducing the weakness of healthy bone. The aim of this study is to demonstrate the efficacy and advantages of …

Sonographie bei Skelettmetastasen - Stellenwert im Vergleich zur Computertomographie und konventionellen Röntgendiagnostik

1990

The value of CT, conventional radiography and ultrasound was compared in 40 patients with 52 skeletal metastases. For superficial lesions, the combination of sonography and conventional radiography was equivalent to CT in showing the extent of bone destruction and soft tissue involvement. As expected sonography was unsatisfactory for deeper lesions. Sonography can provide useful information for planning radiation therapy for superficial lesions, but it does not replace conventional radiography.

Characterization of LiF and CaF2 surfaces using MIES and UPS (HeI)

1998

Metastable impact electron spectroscopy (MIES) and UPS (HeI) in combination with ab initio calculations (CRYSTALcode) were applied to study surface and bulk defects in LiF and CaF2. The investigated stoichiometric, defective and doped surfaces are LiF, LiF doped with Mg, and CaF2. The experimental information obtained on the electronic structure of stoichiometric and defective surfaces of LiF (100), LiF on W (110) and CaF2 (111) is discussed on the basis of the ab initio calculations. MIES spectra show features from Li agglomerates on the surface of electron bombarded LiF. The electronic structure of the LiF:Mg single crystal shows additional features above the valence band maximum caused b…

The energy transfer to the luminescence centers in PbWO4

1998

Abstract The luminescence spectra, rise and decay kinetics and the yield of luminescence in undoped PbWO 4 crystals were studied after pulsed electron beam irradiation. The luminescence intensity rise observed after irradiation pulse showed two mechanisms—excitonic relaxation and electron–hole recombination—were involved in the formation of the excited states of the blue luminescence centers. It is proposed that the excited states of WO 3 and WO 2− 4 luminescence centers were formed from some intermediate metastable state.

THE IMPACT OF NUMBER OF LYMPH NODE REMOVED IN THE DETECTION OF LYMPHNODE METASTASIS: A SENSITIVITY CURVE ANALYSIS.

2014

Scopo del lavoro To assess the correct number of lymph nodes (LNs) to removed at Radical Cystectomy (RC) to ensure an accurate lymph nodes metastasis (LNM) staging. Materiali e metodi Between 1995 and 2012, 1016 RC for bladder cancer (BCa) were completed at a single tertiary care institution. Demographical, clinical and pathological variables were recorded for each patient. The relationship between the number of removed LNs and the probability to find a LNI at definitive pathology examination was assessed by receiver operating characteristic (ROC) analyses. The ROC curve coordinates were used to graph the probability of finding LNI according to the number of LNs removed and examined with a …

Commentary on: Microwave Ablation for Metastatic Spinal Tumors

2021

Ultrapotassic volcanism from the waning stage of the Neotethyan subduction: a key study from the Izmir-Ankara-Erzincan suture belt, central northern …

2016

Upper Cretaceous volcano-sedimentary successions in the Central Pontides of Turkey, related to the closure of the Tethys Ocean, include a variety of alkaline ultrapotassic igneous rocks that have been classified as leucititic, lamprophyric and trachytic based on their mineral paragenesis. Although the ultrapotassic rocks display a range of K 2 O contents (0·9–8·4 wt %) that may partly reflect alteration processes, they display subduction-related trace element signatures characterized by significant enrichment of large ion lithophile elements and light rare earth elements relative to high field strength elements and heavy rare earth elements and depletion of Nb and Ta. However, their initial…