Infrared phonon activity in pristine graphite

We study experimentally and theoretically the Fano-shaped phonon peak at 1590 cm$^{-1}$ (0.2 eV) in the in-plane optical conductivity of pristine graphite. We show that the anomalously large spectral weight and the Fano asymmetry of the peak can be qualitatively accounted for by a charged-phonon theory. A crucial role in this context is played by the particle-hole asymmetry of the electronic $\pi$-bands.Comment: 5 pages, 4 figures, 1 tabl

Optical determination of the relation between the electron-boson coupling function and the critical temperature in high Tc_c cuprates

We take advantage of the connection between the free carrier optical conductivity and the glue function in the normal state, to reconstruct from the infrared optical conductivity the glue-spectrum of ten different high-Tc cuprates revealing a robust peak in the 50-60 meV range and a broad con- tinuum at higher energies for all measured charge carrier concentrations and temperatures up to 290 K. We observe that the strong coupling formalism accounts fully for the known strong temperature dependence of the optical spectra of the high Tc cuprates, except for strongly underdoped samples. We observe a correlation between the doping trend of the experimental glue spectra and the critical temperature. The data obtained on the overdoped side of the phase diagram conclusively excludes the electron-phonon coupling as the main source of superconducting pairing.Comment: Accepted for publication in Phys. Rev.

A Multi Criteria Decision Analytic (MCDA) approach to combining evidence and patient preferences for cancer prevention and treatment: an application to prostate cancer screening

A 72-year-old man, edentulous in the maxilla for 20 years, presented himself at his dentist in 2006 with complaints concerning retention of his upper denture. The placement of implants was only possible if bone augmentation was undertaken; this was definitively rejected by the man. As an alternative, Muchor anchors were placed, but these did not provide an adequate solution to the retention problem. In the end, 2 palatal implants were placed, with magnetic anchoring. One year later, the man was very satisfied with this solution

Optical Integral in the Cuprates and the Question of Sum Rule Violation

Much attention has been given to a possible violation of the optical sum rule in the cuprates, and the connection this might have to kinetic energy lowering. The optical integral is composed of a cut-off independent term (whose temperature dependence is a measure of the sum rule violation), plus a cut-off dependent term that accounts for the extension of the Drude peak beyond the upper bound of the integral. We find that the temperature dependence of the optical integral in the normal state of the cuprates can be accounted for solely by the latter term, implying that the dominant contribution to the observed sum rule `violation' in the normal state is due to the finite cut-off. This cut-off dependent term is well modeled by a theory of electrons interacting with a broad spectrum of bosons.Comment: some clarifications and minor additions are offered in the final (published) versio

The cleavage surface of the BaFe_(2-x)Co_(x)As_(2) and Fe_(y)Se_(1-x)Te_(x) superconductors: from diversity to simplicity

We elucidate the termination surface of cleaved single crystals of the BaFe_(2-x)Co_(x)As_(2) and Fe_(y)Se_(1-x)Te_(x) families of the high temperature iron based superconductors. By combining scanning tunneling microscopic data with low energy electron diffraction we prove that the termination layer of the Ba122 systems is a remnant of the Ba layer, which exhibits a complex diversity of ordered and disordered structures. The observed surface topographies and their accompanying superstructure reflections in electron diffraction depend on the cleavage temperature. In stark contrast, Fe_(y)Se_(1-x)Te_(x) possesses only a single termination structure - that of the tetragonally ordered Se_(1-x)Te_(x) layer.Comment: 4 pages, 4 figure

Imaging of the Lymphatic Vessels for Surgical Planning:A Systematic Review

Background Secondary lymphedema is a common complication after surgical or radiotherapeutic cancer treatment. (Micro) surgical intervention such as lymphovenous bypass and vascularized lymph node transfer is a possible solution in patients who are refractory to conventional treatment. Adequate imaging is needed to identify functional lymphatic vessels and nearby veins for surgical planning. Methods A systematic literature search of the Embase, MEDLINE ALL via Ovid, Web of Science Core Collection and Cochrane CENTRAL Register of Trials databases was conducted in February 2022. Studies reporting on lymphatic vessel detection in healthy subjects or secondary lymphedema of the limbs or head and neck were analyzed. Results Overall, 129 lymphatic vessel imaging studies were included, and six imaging modalities were identified. The aim of the studies was diagnosis, severity staging, and/or surgical planning. Conclusion Due to its utility in surgical planning, near-infrared fluorescence lymphangiography (NIRF-L) has gained prominence in recent years relative to lymphoscintigraphy, the current gold standard for diagnosis and severity staging. Magnetic resonance lymphography (MRL) gives three-dimensional detailed information on the location of both lymphatic vessels and veins and the extent of fat hypertrophy; however, MRL is less practical for routine presurgical implementation due to its limited availability and high cost. High frequency ultrasound imaging can provide high resolution imaging of lymphatic vessels but is highly operator-dependent and accurate identification of lymphatic vessels is difficult. Finally, photoacoustic imaging (PAI) is a novel technique for visualization of functional lymphatic vessels and veins. More evidence is needed to evaluate the utility of PAI in surgical planning.</p

In-plane optical spectral weight transfer in optimally doped Bi2_{2}Sr2_{2}Ca2_{2}Cu3_{3}O10_{10}

We examine the redistribution of the in-plane optical spectral weight in the normal and superconducting state in tri-layer \bbb (Bi2223) near optimal doping ($T_c$ = 110 K) on a single crystal via infrared reflectivity and spectroscopic ellipsometry. We report the temperature dependence of the low-frequency integrated spectral weight $W(\Omega_c)$ for different values of the cutoff energy $\Omega_c$. Two different model-independent analyses consistently show that for $\Omega_c$ = 1 eV, which is below the charge transfer gap, $W(\Omega_c)$ increases below $T_c$, implying the lowering of the kinetic energy of the holes. This is opposite to the BCS scenario, but it follows the same trend observed in the bi-layer compound \bb (Bi2212). The size of this effect is larger in Bi2223 than in Bi2212, approximately scaling with the critical temperature. In the normal state, the temperature dependence of $W(\Omega_c)$ is close to $T^2$ up to 300 K