9 research outputs found
[Arthroscopy of the temporomandibular joint]
U ovom radu opisana je metoda direktne vizualne inspekcije temporomandibularnog zgloba (artroskopija) pomoću »rod-lens« optičkog sistema. Penetrira se u gornjem dijelu zgloba pomoću trokara koji je okružen kanilom i to u projekciji terminalne šarnirske osi, nakon čega se trokar izvuče, a kroz kanilu provuče optička cijev. Artroskopija je učinjena u 44 bolesnika (49 zglobova). Na osnovi dobivenih rezultata, uspoređenih s radiogramima, autor je zaključio kako je jedino artros kopijom moguće točno diferenciijalno dijagnostički utvridti razliku između osteoartroze i artritisa, što je veoma važno za izbor terapije.A method of direct visual inspection of the temporomandibular
joint (arthroscopy) using a rocWens optical system is described. Penetration was made into the upper part of the articulation by means of a trocar surrounded by a cannula, i.e. in the terminal axis projection. Subsequently, the trocar was withdrawn and an optical tube inserted through the cannula. Arthroscopy was carried out in 44 patients(49 joints). On the basis of the results thus obtained, and compared to radiograms, conclusion has been made that arthroiscopy is the only method available allowing the difference between osteoarthrosis and arthritis to be precisesely established by differential diagnosis, which is of an utmost importance for proper thereapy to be choisen
High-resolution photoemission from a tunable quantum well: Cu(111)/Na
High-resolution photoemission (ΔE=5 meV) at a low photon energy (3.82 eV) is used to probe discrete quantum-well-type subband states near, below, and above EF for Cu(111) covered with 2 ML or less of Na. A subband characteristic of the monolayer range shifts gradually to lower energy as the coverage is increased, extending below the Fermi level for coverages above 0.85 ML. Combined with previous observations of shifts for filled and empty states the present results show that the Na monolayer has continuously tunable quantum-well state energies. Beyond the monolayer range quantum-well states characteristic of both one and two atomic layers are observed, indicating growth of the second layer via monolayer high islands. A small downshift, by 25 meV, with increasing coverage in the second layer is ascribed to an increase of the island size. Lorentzian photoemission line shapes are observed for well-ordered samples. The linewidth varies linearly with temprature in the probed range (130–295 K) and this is ascribed to the phonon contribution to the width. Structural disorder leads to an asymmetric line, which is Lorentzian on the steeper, low-kinetic-energy side
Photoelectron driven acoustic surface plasmons in p(2x2)K/Be(0001): Ab initio calculations
We report on low-energy dynamical surface response properties of the p(2
72)K/Be(0001) system calculated within a first-principles approach. It is shown that a partly occupied adsorbate-induced quantum-well band dramatically affects the dynamical properties of the beryllium surface. We demonstrate clear evidence that the observed anomalous features in photoemission spectra of this and a similar system can be explained by acoustic surface plasmon excitations
Photoelectron driven acoustic surface plasmons in p(2x2)K/Be(0001): Ab initio calculations
We report on low-energy dynamical surface response properties of the p(2
72)K/Be(0001) system calculated within a first-principles approach. It is shown that a partly occupied adsorbate-induced quantum-well band dramatically affects the dynamical properties of the beryllium surface. We demonstrate clear evidence that the observed anomalous features in photoemission spectra of this and a similar system can be explained by acoustic surface plasmon excitations
Sodium and potassium monolayers on Be(0001) investigated by photoemission and electronic structure calculations
Photoemission spectra show that Be(0001) surface states shift to lower energy with increasing Na or K coverage in the monolayer range. At an intermediate monolayer coverage a quantum well state appears near the Fermi edge and shifts to lower energy reaching saturation energy at full monolayer coverage. At full monolayer coverage low energy electron diffraction shows 2 X 2 order for K while Na forms an incommensurate close-packed structure aligned with the substrate. As a result of the different structures, the photoemission spectra show qualitative differences that are explained by diffraction. First-principles calculations for Be(0001) and p(2 X 2)K/Be(0001) reproduce reasonably the measured energy shifts and dispersions. Spectra recorded for the shallow alkali-metal core levels show that the adlayer is inhomogeneous in art intermediate coverage range. While this is not noted when the valence state energies are measured a linewidth change observed for one of the surface states is ascribed to this inhomogeneity. It is suggested that the onset of inhomogeneity is associated with the occupation of states in the quantum well band. Occupation of these states, which are highly localized to the adlayer, gives metal character to the layer over an increasing area as the coverage is increased making the film homogeneous at high monolayer coverage. An anomalous emission line is observed for both Na and K as a low energy companion to the quantum well state line becoming increasingly separated from this as the coverage increases. We suggest that the satellite is due to an energy loss associated with collective oscillations in the overlayer