Extraction and STM Imaging of Spherical Giant Fullerenes.

High-temperature, high-pressure extracts of soot produced by the Krätschmer-Huffman technique (KH carbon) were characterized by mass spectrometry and imaging with scanning tunneling microscopes (STMs). The mass spectra of these samples are similar to those of ambient-pressure, high-boiling-point solvent extractions, supporting the idea that solvent temperature and possibly pressure are key parameters in extraction of the giant fuilerenes. The STM images show that the giant fullerenes in these samples are roughly spherical in shape and range in diameter from approximately 1 to 2 nanometers, corresponding to fullerenes containing 60 to 330 atoms. No evidence of bucky tubes was found.

Attempts to grow optically coupled Fibonacci-spaced InGaAs/GaAs quantum wells result in surface gratings.

An instability in the growth of nonperiodic InGaAs/GaAs multiple quantum well samples, ordinarily of high-quality when grown with equal periods of order of half the wavelength of light in the material, leads to a dramatic microscopic, self-organized surface grating. This effect was discovered while growing quantum wells with two unequal barrier lengths arranged in a Fibonacci sequence to form an optical quasicrystal. A laser beam incident normal to the surface of the sample is diffracted into a propeller-shaped pattern. The sample surface has a distinctly cloudy appearance when viewed along one crystal axis but is mirror-like when the sample is rotated 90 degrees. The instability results in a five-fold increase in the absorption linewidth of the heavy-hole exciton transition. Atomic force microscopy, transmission electron microscopy, and scanning electron microscopy were used to study the samples.

Nuclear and cytoplasmic expression of ErbB-4 in prostate cancer.

PURPOSE: To evaluate cytoplasmic and nuclear ErbB-4 expression in prostate cancer specimens and its association with outcome. BASIC PROCEDURES: Specimens of 50 prostate cancer patients were investigated for ErbB-4 overexpression using Immunohistochemistry staining. Cytoplasmic and nuclear staining was graded as 0-3 according to its intensity. The prognostic parameters were tumor stage, PSA level, Gleason score, probability of positive lymph nodes (Partin's tables and Roach equation), and 5-year disease free survival (Kattan nomogram). MAIN FINDINGS: Overexpression of ErbB-4 (> or = 1) was detected in 30 (60%) patients and overexpression using cytoplasmic and nuclear staining was > or = 2 in 19 (38%) and 17 (34%) patients, respectively. In only one third of the specimens was there any similarity between the 2 types of staining. Advanced tumor stage, high pretreatment PSA levels and high Gleason scores were evenly distributed among the patients with low (< or = 1) and intermediate/high (> or = 2) ErbB-4 expression. The probability of lymph node involvement and 5-year disease free survival were similar in both types of staining. PRINCIPAL CONCLUSIONS: ErbB-4 was overexpressed (cytoplasmic and nuclear staining) in approximately one third of prostate cancer patients. The rate of similarity between the 2 staining types was only 33%: overexpression was evenly distributed among intermediate/high and low risk prostate cancer patients with both staining methods.

Imaging response during therapy with radium-223 for castration-resistant prostate cancer with bone metastases-analysis of an international multicenter database.

BACKGROUND: The imaging response to radium-223 therapy is at present poorly described. We aimed to describe the imaging response to radium-223 treatment. METHODS: We retrospectively evaluated the computed tomography (CT) and bone scintigraphy response of metastatic castration-resistant prostate cancer (CRPC) patients treated with radium-223, in eight centers in three countries. RESULTS: A total of 130 patients were included, the majority (n=84, 65%) received radium-223 post docetaxel. Thirty-four of 99 patients with available data (34%) received concomitant abiraterone or enzalutamide. A total of 54% (n=70) patients completed the planned six injections of radium-223. In patients with available data, a transient increase in bone metastases-related pain was observed in 27% (n=33/124) and an improvement of bone metastases-related pain on treatment with radium-223 was noted in 49% of patients (n=61/124). At 3 and 6 months of treatment with radium-223, bone imaging showed stable disease in 74% (n=84/113) and 94% of patients (n=93/99) with available data, respectively. An increase in the number of bone lesions was documented at 3 months compared with baseline in 26% (n=29/113) and at 6 months compared with 3 months in 6% of patients (n=6/99), respectively. Radiological extraskeletal disease progression occurred in 46% of patients (n=57/124) with available CT data at 3 and/or 6 months. CONCLUSIONS: Progression of bone metastases during radium-223 therapy is uncommon. A bone flare (pain and/or radiological) may be noted during the first 3 months, and should not be confused with progression. Imaging by CT scan should be considered after three and six doses of radium-223 to rule out extraskeletal disease progression.

Spontaneous regression of retroperitoneal metastases from a primary pure anaplastic seminoma: a case report.

Spontaneous regression of pure seminoma metastases is a rare phenomenon, with only a few cases reported to date. To the best of our knowledge, this is the first report of regression of anaplastic pure seminoma metastases located in the retroperitoneum. We present a 27-year-old man, a marihuana smoker, with metastatic pure anaplastic seminoma in the high retroperitoneal lymph nodes. After orchiectomy, his metastases regressed with no medication. Several mechanisms are suggested to explain this phenomenon, which still remains elusive.

Recovery of the refractive-index profile of an optical waveguide from the measured coupling angles.

A method is presented for calculating the profile of the refractive index of an optical waveguide, n(x) = n(0) + f(x), from the measured coupling angles for any physically justified functional form of f(x). As an example, we present the results of a Ti in-diffused LiNbO(3) waveguide for which f(x) fits the sum of two Gaussians.

Analysis of bistability in a ring-channel waveguide.

We present the theory of operation of a ring-channel waveguide coupled to two line channels in which the ring has an optical-power-dependent refractive index. The bistability of the device is analyzed in terms of the geometry of the ring, the nonlinear properties of the ring or the cladding, the coupling coefficients, and the optical losses. A numerical example demonstrates that when InSb is used at a wavelength of 5microm, switching can take place with a power level of 1.5microW.

High efficiency input-output prism waveguide coupler: an analysis.

The theory and experimental results of the performance of a practical prism waveguide input-output coupler are presented. The coupling scheme, which results in a 94% coupling efficiency, uses a single prism for both input and output coupling, with the light propagating 1 cm in the LiNbO(3) Ti in diffused waveguide.

Effects of incident angle on readout in magnetooptic storage media.

The effects of incident angle on the readout SNR of a magnetooptic storage system employing the differential detection system were theoretically investigated. The most important parameters which depend on incident angle were found to be the Kerr reflectance and the phase difference between the two components of the reflected wave. In particular, the phase difference was found to depend strongly on incident angle for structures which are strongly antireflective.

Effect of carrier diffusion on the nonlinear response of optical waveguides.

Using a self-consistent numerical method, we calculate the carrier-density-dependent changes in the propagation constant of a TE mode in a symmetric slab semiconductor waveguide. By modeling the nonlinearity with the plasma theory, the effect of transverse carrier diffusion on the nonlinear response of a waveguide is investigated for typical waveguide parameters.

Long-range surface magnetoplasmons in thin nickel films.

We present the results of a theoretical and experimental investigation of long-range surface magnetoplasmons in thin, magnetic metal films. With a transversely applied magnetic field, the reflectance modulation measurements from prism-coupled modes in nickel films are in agreement with the theory. The reflectance modulation is the same order of magnitude for prism-coupled long-range and single-interface magnetoplasmons.

Determination of optical constants by angle scanning reflectometry.

Reflectance measurements made on an Fe film over a wide range of angles of incidence are curve-fitted to extract the optical constants n and k. Problems with surface oxide layers are eliminated by making the reflectance measurements through the substrate. The experimental uncertainties of n and k are determined by a rigorous x(2) analysis. The experimentally determined optical constants are found to be considerably larger than values found in the literature.

Compact scanning-force microscope using a laser diode.

We describe a compact scanning-force microscope in which the element that senses the amplitude of vibration of a tip interacting with force gradients is the cavity of a single-mode laser diode and its integrally built photodiode.

Optical probing of magnetic inert layers.

The thickness of a magnetic inert layer on top of a ferrite head sample was measured by probing the longitudinal Kerr effect as a function of the angle of incidence of a laser beam. Our computerized measuring system used a simple single-detector setup to derive polarization information from a Kerr-reflected beam as the incident angle was scanned. The results were analyzed using a general theory of reflection from magnetic stratified media. The experimental results indicate that the possible inert-layer thickness values are given by (50 +/- 10) + 60 x N nm, where the order N equals 0, 1, 2, 3, or 4.

Experimental observation of the long-range surface-plasmon polariton.

The propagation and attenuation constants of long-range surface-plasmon polaritons propagating on thin metal films have been measured for several film thicknesses by using a hemispherical retroreflecting coupler. The results are in agreement with our theoretical dispersion curves, which predict that the attenuation constant of this mode can decrease by a factor of 63 relative to that obtained with a thick metal film.

Novel system for coupling to surface-plasmon polaritons.

A novel system for coupling to surface-plasmon polaritons has been designed, fabricated, and assembled. Microcomputer controlled electronics provide for accurate and repeatable angular positioning of the waveguide coupler with respect to the incident beam and for precise angular registration of detector output signals. The optical components, combined with a retroreflecting spherical-surface coupling prism, give apertured control of the beam profile at the coupling interface.