Serum albumin (SA) accumulation by bronchogenic tumours: a tracer technique may help with patient selection for SA-delivered chemotherapy

Systemic toxicity and inadequate tumour uptake of chemotherapeutic agents limit effective therapy of disseminated malignant disease. We seek to use macromolecules for improved delivery of therapeutic agents to tumours, and hope to use radiotracer procedures to identify those malignancies able to accumulate the transport molecule. A literature search identified in vitro and animal experimental data which indicated that serum albumin is taken up in malignancies. Selected cytostatic drugs can be bound to albumin, which suggests the suitability of the molecule as a potential transport vehicle. We therefore evaluated indium-111 labelled human serum albumin (HSA) to determine the frequency of its accumulation in bronchogenic tumours. Single-photon emission tomographic (SPET) images were obtained in 23 patients 48 h after intravenous injection of 1.5 mCi 111In diethylenetriamine penta-acetic acid (DTPA)-HSA. SPET imaging with technetium-99m labelled erythrocytes was included in the protocol to assess the influence which vascularity has on the HSA-based images. All patients went on to surgery. We documented the histological diagnosis, T-stage and differentiation grade. The scintigraphic examination demonstrated HSA uptake in three squamous cell carcinomas and four adenocarcinomas. Of these, six malignancies accumulating HSA had 2.2-5.4 times, the tracer concentrations observed in comparable background regions. Small cell carcinoma failed to accumulate the labelled HSA during the 2-day scintigraphic evaluation. The HSA images did not appear to represent tumour vascularity. T-stage and differentiation grade failed to predict which tumours would demonstrate HSA uptake.(ABSTRACT TRUNCATED AT 250 WORDS)     

Remote Induction Sounding of Hanna Underground Coal Burn II, Phase 1, Employing Pseudonoise/ Cross-Correlation Techniques

An underground coal gasification site near Hanna, WY, was remotely sounded with an induction system at the surface one year after the burn. An estimated 1800 tons (40 000 cu. ft.) of coal 275 ft. deep had been converted to low-Btu gas. The wideband loop-loop system employed pseudonoise signals at the transmitter and cross-correlation over 0-50 kHz at the receiver to obtain time signatures in the field. These time-domain impulse responses were converted to frequency responses on a Fourier analyzer system for ease of interpretation. Single-frequency responses at approximately 1 and 5 kHz were extracted from these wideband responses for further investigation. Skindepth calculations showed these to be effective for probing at these depths. Fou in-line traverses conducted over the Hanna II, Phase 1 Site produced strong anomalies of at least 8-to-1 at approximately 5 kHz. Interpretation of these anomalies agrees quite well in location and shape with chemical modeling estimates from north to south. However, these soundings support the conclusion that the burn may have protruded another 5 m to the west from the chemical estimate. The centroid of the burn region was obtained by averaging anomaly values weighted by their location.     

14C/12C-ratios in organic matter and hydrocarbons extracted from dated Lake sediments

Extractable organic matter (lipids) and hydrocarbons isolated from lake sediments were investigated by AMS by directly evaporating the extracts onto targets. Carbon-14 ages obtained for the postglacial sediments of Lake Baldegg (Switzerland) are in good agreement with results from pollen stratigraphy. The hydrocarbons contained in modern sediments of Lake Constance were found to be largely of fossil origin.     

The impact of water released from boehmite nanoparticles during curing in epoxy-based nanocomposites

The enhancing effect on mechanical properties of boehmite (γ-AlOOH) nanoparticles (BNP) in epoxy-based nanocomposites on the macroscopic scale encouraged recent research to investigate the micro- and nanoscopic properties. Several studies presented different aspects relatable to an alteration of the epoxy polymer network formation by the BNP with need for further experiments to identify the mode of action. With FTIR-spectroscopic methods this study identifies interactions of the BNP with the epoxy polymer matrix during the curing process as well as in the cured nanocomposite. The data reveals that not the BNP themselves, but the water released from them strongly influences the curing process by hydrolysis of the anhydride hardener or protonation of the amine accelerator. The changes of the curing processes are discussed in detail. The changes of the curing processes enable new explanation for the changed material properties by BNP discussed in recent research like a lowered glass transition temperature region (T_g) and an interphase formation.     

Determination of the refractive index of single crystal bulk samples and micro-structures

We present comparative studies for the exact determination of the refractive index of single crystals using spectroscopic ellipsometry and photonic-mode-structure investigations by means of spatially resolved photoluminescence spectroscopy, especially in the near band-gap spectral range. By applying such complementary methods we can overcome the uncertainties in the determination of the bulk refractive index introduced by surface properties. The physical effects used are the electromagnetic field reflection used by spectroscopic ellipsometry at large scale planar single crystals and the whispering-gallery-mode formation by total internal reflection in confined micro-structures. We demonstrate the applicability of such studies using the example of uniaxial ZnO bulk samples and micro-wires. By assuming a surface near region with electronic properties different from the bulk material, the method presented here gives the refractive index dispersion for both types of samples in an energy range from 1 to 3.4 eV.     

Recursive nearest neighbor search in a sparse and multiscale domain for comparing audio signals

We investigate recursive nearest neighbor search in a sparse domain at the scale of audio signals. Essentially, to approximate the cosine distance between the signals we make pairwise comparisons between the elements of localized sparse models built from large and redundant multiscale dictionaries of time-frequency atoms. Theoretically, error bounds on these approximations provide efficient means for quickly reducing the search space to the nearest neighborhood of a given data; but we demonstrate here that the best bound defined thus far involving a probabilistic assumption does not provide a practical approach for comparing audio signals with respect to this distance measure. Our experiments show, however, that regardless of these non-discriminative bounds, we only need to make a few atom pair comparisons to reveal, e.g., the origin of an excerpted signal, or melodies with similar time-frequency structures.     

Multi-view structure-from-motion for hybrid camera scenarios

We describe a pipeline for structure-from-motion (SfM) with mixed camera types, namely omnidirectional and perspective cameras. For the steps of this pipeline, we propose new approaches or adapt the existing perspective camera methods to make the pipeline effective and automatic. We model our cameras of different types with the sphere camera model. To match feature points, we describe a preprocessing algorithm which significantly increases scale invariant feature transform (SIFT) matching performance for hybrid image pairs. With this approach, automatic point matching between omnidirectional and perspective images is achieved. We robustly estimate the hybrid fundamental matrix with the obtained point correspondences. We introduce the normalization matrices for lifted coordinates so that normalization and denormalization can be performed linearly for omnidirectional images. We evaluate the alternatives of estimating camera poses in hybrid pairs. A weighting strategy is proposed for iterative linear triangulation which improves the structure estimation accuracy. Following the addition of multiple perspective and omnidirectional images to the structure, we perform sparse bundle adjustment on the estimated structure by adapting it to use the sphere camera model. Demonstrations of the end-to-end multi-view SfM pipeline with the real images of mixed camera types are presented.     

Thermoelectric properties of hot-pressed Ruddlesden-Popper phases CaO(CaMnO3)m

We investigated the Ruddlesden-Popper series CaO(CaMnO₃)_m with m = 1, 2, 3, ∞, to study the impact of the varying amounts of CaO layers on their thermoelectric properties. Previous studies showed that highly dense samples are difficult to obtain due to the refractory nature of these materials. In this study, we managed to obtain dense pellets during a classical hot-pressing step, if and only if the samples were subjected to extended ball-milling prior to pressing, resulting in crystallite sizes of 30–35 nm after hot-pressing. The sample with the largest amount of CaO layers (m = 1) had the lowest electrical and thermal conductivity, and the highest Seebeck coefficient, as predicted. Ultimately the perovskite CaMnO₃ (m = ∞, no CaO layers) exhibited the best thermoelectric properties.