Comparison of estrogen receptor levels in breast cancer samples from mastectomy and frozen section specimens

Estrogen receptor assays were performed in 13 cases of carcinoma of the breast on two samples of tumor tissue. One was the usual sample obtained from the specimen submitted for frozen section. The other sample was taken from tumor tissue remaining in the mastectomy specimen. Eight of the 13 cases were positive for estrogen receptors determined by the dextran-coated charcoal method. The initial frozen section specimens showed estrogen receptor levels 1.6 to 6.5 times greater than the mastectomy specimens, which were lower in seven of eight cases. One case showed no change in estrogen receptor levels. The devitalization of the breast during mastectomy, mechanical and possible chemical injury to the tumor, and delays in obtaining the mastectomy specimen are factors that cause a decreaSE in receptor levels. A tumor with a low level of estrogen receptor might possibly yield a false negative result in a mastectomy specimen.     

Determination of the Bingham parameters of an electrorheological fluid in an axial flow concentric-cylinder rheometer

Electrorheological (ER) fluids are fluids that undergo changes in their rheological properties in the presence of an applied electrical field. The change in the flow properties with an applied electrical field has led to their being investigated for use as ‘smart’ lubricants. The Bingham model is currently used to describe the behaviour of these fluids. In this work, the Bingham model parameters of a commercially available ER fluid are obtained using an axial flow concentric-cylinder rheometer. Two methods are used to determine these parameters. One is the Weissenberg (—Rabinowitsch) method applied to thin annular slits, to obtain corrected stress—strain rate information. The other method involves directly fitting the velocity—pressure curve data to the axial flow rate equation of a Bingham fluid through concentric cylinders. The results obtained by these two methods differ by as much as 49.4 and 63.5% for the yield stress and viscosity, respectively. It is observed for this ER fluid that the yield stress increases according to a power law relationship with the applied electrical field. The viscosity appears to decrease linearly with an increase in the applied electrical field.     

Ignorance is no Defence, but is Inaccessibility? On the Accessibility of National Laws to Foreign Online Publishers

The article examines, first, to what extent the legal exposure of online actors to multiple foreign laws creates a legal obligation on states to make their laws easily accessible to them and whether a state by failing to do so breaches any human rights. Second, it is examined what 'easy accessibility' actually entails. The discussion builds upon the premise that the Internet has created an environment where transnational trade or publications are no longer the prerogative of resource-rich multinational companies with large inhouse legal departments to advise them on their respective legal position in different jurisdictions. Yet, there is growing worldwide consensus that online content providers have to comply with the laws of the places where their sites can be accessed. This raises the issue of whether the legal expectation of states on foreign online actors goes, or should go, hand-in-hand with an obligation to cater for the special regulatory needs of foreign actors.     

The effect of amorphous chalcogenides on mechanical and anticorrosive properties of protective organic coatings containing high amounts of zinc metal particles

The objective of this paper concerns reduction of zinc metal content in organic coatings while preserving their high anticorrosive efficiency. The two goals can be achieved by using amorphous chalcogenides as components of the protective coating. Special attention was paid to materials containing Ge₂₀Se₈₀, Ge₃₀Se₇₀ and Ge₄₀Se₆₀, which were characterized by physico-chemical properties. An epoxy ester resin was used as binder for the investigated organic coatings. Organic coatings were prepared by combining zinc metal with amorphous chalcogenides. The resistance of the prepared films was evaluated using the results of mechanical tests. The anticorrosive efficiency of the prepared films was evaluated using the results of direct corrosion tests. Thus the following conclusion can be made from the results of anti-corrosive tests: the higher the pigment volume concentration of amorphous chalcogenides in the coatings, the higher the protective performance of the paint against corrosion.     

Quantitative comparison of energy-filtering transmission electron microscopy and atom probe tomography

Whereas transmission electron microscopy (TEM) is a well established method for the analysis of thin film structures down to the sub-nanometer scale, atom probe tomography (APT) is less known in the microscopy community. In the present work, local chemical analysis of sputtered Fe/Cr multilayer structures was performed with energy-filtering transmission electron microscopy (EFTEM) and APT. The single-layer thickness was varied from 1 to 6 nm in order to quantify spatial resolution and chemical sensitivity. While both the methods are able to resolve the layer structure, even at 2 nm thickness, it is demonstrated that the spatial resolution of the APT is about a factor of two, higher in comparison with the unprocessed EFTEM data. By calculating the influence of the instrumental parameters on EFTEM images of model structures, remaining interface roughness is indicated to be the most important factor that limits the practical resolution of analytical TEM.     

Expressions for coefficients of electrorheological fluid dampers

Useful expressions are developed for the damping coefficient of two types of viscous dampers that contain electrorheological (ER) fluids. The damping action in the first type occurs in flow between stationary parallel plates; the second type has annular flow between two stationary concentric cylinders. For ER fluid control, an electric field is applied across the gap in which the fluid flow occurs. The solution for the concentric cylinder damper is based on a thin gap approximation. These solutions may facilitate solving mechanical systems problems, using ER fluids, and demonstrate the controllability of ER dampers.     

Optical properties of highly scattering media determined from changes in attenuation, phase, and modulation depth

The optical properties of scattering media determine the attenuation (A) and the transit time (?t?) of light reflected from the medium as well as the phase (?) and modulation depth (M) of an intensity-modulated lightwave. Our primary finding is that the ratio of changes in A, ?, and M is approximately independent of the scattering properties and gives a good estimate of the absorption coefficient. These changes can be induced either by small changes in the absorption coefficient of the medium, by the tuning of the wavelength, or by changes in the light source-detector distance. The application for the in vivo monitoring of hemoglobin and oxyhemoglobin concentrations in human tissue is discussed.     

Analysis of Gasolines by FT-IR Spectroscopy

An experimental and computational protocol was established for the simultaneous determination of several key gasoline properties from a single Fourier transform infrared (FT-IR) spectrum. The study has shown that midband FT-IR spectroscopy combined with multivariate calibration analysis is a versatile, efficient, and accurate technique for the simultaneous estimation of key gasoline properties within about 1 min with less than 2 mL of sample. The FT-IR-derived values of gasoline properties include research and motor octane numbers, aromatic, olefinic, and saturated hydrocarbon content, benzene content, and concentrations of ethanol, methyl tert-butyl ether, and total oxygen. Concentrations of other oxygenated compounds are expected to be equally predictable. However, since these oxygen-containing species have not been adequately represented among the currently commercially available gasoline samples, their calibration may only be achieved using laboratory fuel blends. Midrange boiling point data may also be estimated. Fuel properties determined by minor concentrations of fuel components, e.g., flash point, sulfur content, etc., may not be modeled because the corresponding FT-IR signals are below detection limits of presented experimental protocol. The precision of this procedure was shown to be comparable to reproducibility of the standard laboratory analyses used for direct measurement of specific fuel properties, with squared correlation coefficient (R(2)) ranging from 0.94 to 0.99 between the two sets of measurements. This new methodology could increase the corresponding output of the petroleum laboratories by a factor of over 200 to 1 while maintaining data integrity and minimizing sample requirements, environmental hazards, and cost.     

Measurement technique for the thermal properties of thin-film diaphragms embedded in calorimetric flow sensors

In diaphragm-based micromachined calorimetric flow sensors, convective heat transfer through the test fluid competes with the spurious heat shunt induced by the thin-film diaphragm where heating and temperature sensing elements are embedded. Consequently, accurate knowledge of thermal conductivity, thermal diffusivity, and emissivity of the diaphragm is mandatory for design, simulation, optimization, and characterization of such devices. However, these parameters can differ considerably from those stated for bulk material and they typically depend on the production process. We developed a novel technique to extract the thermal thin-film properties directly from measurements carried out on calorimetric flow sensors. Here, the heat transfer frequency response from the heater to the spatially separated temperature sensors is measured and compared to a theoretically obtained relationship arising from an extensive two-dimensional analytical model. The model covers the heat generation by the resistive heater, the heat conduction within the diaphragm, the radiation loss at the diaphragm’s surface, and the heat sink caused by the supporting silicon frame. This contribution summarizes the analytical heat transfer analysis in the microstructure and its verification by a computer numerical model, the measurement setup, and the associated thermal parameter extraction procedure. Furthermore, we report on measurement results for the thermal conductivity, thermal diffusivity, and effective emissivity obtained from calorimetric flow sensor specimens featuring dielectric thin-film diaphragms made of plasma enhanced chemical vapor deposition silicon nitride.