97 research outputs found
Anisotropic optical properties of single-crystal GdBa2Cu3O7-delta
The optical spectrum of reduced-T(c) GdBa2Cu3O7-delta has been measured for polarizations parallel and perpendicular to the ab plane. The sample was an oxygen-deficient single crystal with a large face containing the c axis. The polarized reflectance from this face was measured from 20-300 K in the spectral region from 30-3000 cm-1, with 300 K data to 30 000 cm-1. Kramers-Kronig analysis was used to determine the spectral dependence of the ab and the c components of the dielectric tensor. The optical properties are strongly anisotropic. The ab-plane response resembles that of other reduced-T(c) materials whereas the c axis, in contrast, shows only the presence of several phonons. There is a complete absence of charge carrier response along c above and below T(c). This observation allows us to set an upper limit to the free-carrier spectral weight for transport perpendicular to the CuO2 planes
The prospects for Yb- and Nd-doped tungstate microchip lasers
Potassium gadolinium and yttrium tungstates doped with trivalent Nd, Yb or Tm ions are widely used crystals for efficient diode-pumped lasers. They are usually oriented along the b crystallographic axis, which is also the N p axis of optical indicatrix. The Np-cut is characterized by a strong thermal lens with opposing signs along Nm and N g [1]. This is unsuited to microchip lasers which require a positive thermal lens for a stable cavity. Therefore, a detailed investigation of thermo-optic effects and microchip laser potential of other crystallographic orientations in tungstate crystals is of interest
Pixantrone-rituximab versus gemcitabine-rituximab in relapsed/refractory aggressive non-Hodgkin lymphoma.
UNLABELLED: We describe the rationale and design of the ongoing randomized, active-controlled, multicenter, Phase III study evaluating the efficacy of pixantrone and rituximab versus gemcitabine and rituximab in patients with diffuse large B-cell lymphoma or follicular grade 3 lymphoma, who are ineligible for high-dose chemotherapy and stem cell transplantation, and who failed front-line regimens containing rituximab. The administration schedule is pixantrone 50 mg/m(2) intravenously (iv.) or gemcitabine 1000 mg/m(2) iv. on days 1, 8 and 15, combined with rituximab 375 mg/m(2) iv. on day 1, up to six cycles. Pixantrone has a conditional European marketing approval for monotherapy in adults with multiple relapsed or refractory aggressive B-cell non-Hodgkin lymphoma. Our trial explores the efficacy of combining pixantrone with rituximab and completes postauthorization measures. TRIAL REGISTRATION NUMBER: NCT01321541
Scaling of Particle and Transverse Energy Production in 208Pb+208Pb collisions at 158 A GeV
Transverse energy, charged particle pseudorapidity distributions and photon
transverse momentum spectra have been studied as a function of the number of
participants (N_{part}) and the number of binary nucleon-nucleon collisions
(N_{coll}) in 158 A GeV Pb+Pb collisions over a wide impact parameter range. A
scaling of the transverse energy pseudorapidity density at midrapidity as
N_{part}^{1.08 \pm 0.06} and N_{coll}^{0.83 \pm 0.05} is observed. For the
charged particle pseudorapidity density at midrapidity we find a scaling as
N_{part}^{1.07 \pm 0.04} and N_{coll}^{0.82 \pm 0.03}. This faster than linear
scaling with N_{part} indicates a violation of the naive Wounded Nucleon Model.Comment: 13 pages, 16 figures, submitted to European Physical Journal C
(revised results for scaling exponents
Systematics of Inclusive Photon Production in 158 AGeV Pb Induced Reactions on Ni, Nb, and Pb Targets
The multiplicity of inclusive photons has been measured on an event-by-event
basis for 158 AGeV Pb induced reactions on Ni, Nb, and Pb targets. The
systematics of the pseudorapidity densities at midrapidity (rho_max) and the
width of the pseudorapidity distributions have been studied for varying
centralities for these collisions. A power law fit to the photon yield as a
function of the number of participating nucleons gives a value of 1.13+-0.03
for the exponent. The mean transverse momentum, , of photons determined
from the ratio of the measured electromagnetic transverse energy and photon
multiplicity, remains almost constant with increasing rho_max. Results are
compared with model predictions.Comment: 16 pages including 4 figure
Spectroscopic and photoluminescence characterization of Eu 3+-doped monoclinic KY(WO4)2 crystal
Monoclinic 2 at% Eu-doped KY(WO4)2 is grown by top-seeded solution growth method. Polarizationresolved absorption and stimulated-emission cross-section spectra are determined for this crystal. Spectroscopic properties of Eu:KY(WO4)2 are modeled within conventional Judd–Ofelt theory, as well as theory of f–f transition intensities for systems with anomalously strong configuration interaction, yielding absorption oscillator strengths, luminescence branching ratios and radiative lifetime of 5D0 state. The impact of excited-state absorption from this state on possibility of laser operation is discussed. Photoluminescent properties of Eu:KY(WO4)2 are determined. This crystal provides intense red emission with CIE coordinates x¼0.670, y¼0.329
Combination of Endobronchial Ultrasound and Modern Cytological Diagnosis in Patients With Intrathoracic Lesions
Objective: To evaluate the effectiveness of endobronchial (EBUS) and endoscopic ultrasound (EUS) in cytomorphological verification of a malignant process using the transbronchial needle aspiration (TBNA) of the lymph nodes and mediastinal organs.Materials and methods: In 2017–2019 we analyzed the cytological samples (standard and cell block) of 172 patients (115 males and 57 females) with an average age of 61 years (25–82 years) in the clinical diagnostic laboratory of Scientific Research Institute – Ochapovsky Regional Clinical Hospital No. 1 (Krasnodar, Russian Federation). Of them 111 were used for immunocytochemical analysis. The majority of the studies (77) were performed in patients with lung cancer in order to identify the stage of the disease. We used combined bronchoscopy under general anesthesia in the operating room with high-frequency ventilation and a rapid on-site evaluation (ROSE).Results: We found the lymph node and mediastinal invasion in 140 (81%) patients who underwent EBUS-EUS TBNA. The non-diagnostic results were obtained in 32 (19%) patients. The combination of EUS and EBUS with TBNA showed the highest effectiveness in the mentioned clinical cases. The sensitivity, specificity, and accuracy of the cytologic analysis during EBUS and EUS with TBNA and no ROSE were 89%, 100%, and 90%, respectively. ROSE reduced the rate of non-diagnostic results and increased the sensitivity (96%), specificity (100%), and accuracy (97%) of the cytologic evaluation.Conclusions: According to the obtained results, we recommend using EBUS-EUS TBNA modalities for morphological verification of the mediastinal lymph nodes as a routine invasive diagnosis component of the preoperative evaluation in patients with lung cancer
Low background detector with enriched 116CdWO4 crystal scintillators to search for double beta decay of 116Cd
A cadmium tungstate crystal boule enriched in Cd to 82% with mass of
1868 g was grown by the low-thermal-gradient Czochralski technique. The
isotopic composition of cadmium and the trace contamination of the crystal were
estimated by High Resolution Inductively Coupled Plasma Mass-Spectrometry. The
crystal scintillators produced from the boule were subjected to
characterization that included measurements of transmittance and energy
resolution. A low background scintillation detector with two CdWO
crystal scintillators (586 g and 589 g) was developed. The detector was running
over 1727 h deep underground at the Gran Sasso National Laboratories of the
INFN (Italy), which allowed to estimate the radioactive contamination of the
enriched crystal scintillators. The radiopurity of a third CdWO
sample (326 g) was tested with the help of ultra-low background high purity
germanium detector. Monte Carlo simulations of double
processes in Cd were used to estimate the sensitivity of an experiment
to search for double decay of Cd.Comment: 24 pages, 13 figures, 3 tables, accepted for publication on Journal
of Instrumentatio
Freeze-Out Parameters in Central 158AGeV Pb+Pb Collisions
Neutral pion production in central 158AGeV Pb+Pb collisions has been studied
in the WA98 experiment at the CERN SPS. The pi0 transverse mass spectrum has
been analyzed in terms of a thermal model with hydrodynamic expansion. The high
accuracy and large kinematic coverage of the measurement allow to limit
previously noted ambiguities in the extracted freeze-out parameters. The
results are shown to be sensitive to the shape of the velocity distribution at
freeze-out.Comment: 5 pages including 3 figures, small changes due to review process,
accepted for publication in Phys.Rev.Let
- …