False negative cytogenetic results following amniocentesis

The effect of feeding rats with cassava diet (tapioca) has been investigated with respect to the activities of superoxide dismutase, catalase and levels of TBARS. By varying the levels of protein in the diet and cyanide content of cassava, the possible role of a high protein diet in the prevention of oxidant stress has been shown. Rhodanese which detoxifes cyanide is also found to be inhibited in rats fed low protein diet while the inhibition was only marginal in the high protein fed groups.     

Density calculation and concentration scale conversions for natural waters

A program is presented that calculates the density of a natural water from its composition. It is based on the recent modeling of the volumetric properties of natural waters at 25°C and 1 bar to high concentrations using Pitzer's equations. The required input is the concentrations of the major solutes of natural waters, that is Na, K, Ca, Mg, Cl, SO₄, HCO₃, and CO₃, expressed in any of the most widely used scales: molinity (grams or moles per kg of solution), molality (moles per kg of water), or molarity (moles or grams per liter). The output consists of the density of the solution, the partial molal volumes of the solutes, and a table in which the input concentrations are converted into all the scales as cited plus the solute mole fractions. The error in t he calculated seawater density is 0.00002 g/cm³, but it increases to about 0.0004 g/cm³ for dense brines. The program then is used to calculate the consequences of the approximation that natural waters behave as pure sodium chloride solutions, both for the computed density and for the concentration conversions.     

Silicon technologies for applications up to millimetre-waves: Some design guidelines

This paper presents some guidelines for the design of silicon circuits, which are able to achieve state of the art performances in the microwave frequency range despite their integration with a standard technology. Firstly, we point out the benefits which may be expected from the large number of available metallic layers, and which make possible the implementation of highly integrated and low loss interconnects and passives. Next, we emphasize the advantages of microwave differential structures: without any increase of the circuit complexity, a very well balanced behaviour can be reached leading to a strong attenuation of common mode parasitic signals. Finally, the interest and the feasibility of mixed-mode circuits (analog with digital) are demonstrated through dedicated designs for microwave frequency synthesis. Christophe Viallon received the M.S. degree and the Ph.D. degree in electrical engineering from Paul Sabatier University, Toulouse, France in 1999 and 2003 respectively. From 2000 to 2004 he was with the Laboratory of Analysis and Architecture of Systems (LAAS), Toulouse, France, where he was conducting research on the optimization of differential circuit topologies for millimeter-wave applications using SiGe BiCMOS technologies. Since 2005, he is an associate professor at Paul Sabatier University, and his researches at the LAAS laboratory are mainly focused on nonlinear microwave integrated circuit design and above-IC passive elements development. éric Tournier was born in Saint-Jean d’Angely, France, in 1970. He received the Engineer degree and the Ph.D. degree both from the Institut National des Sciences Appliqu, Toulouse, France, in 1993 and 1998 respectively. Since September 1998, he has been an associate professor of electrical engineering at the university of Toulouse, and a researcher at the Laboratoire d’Analyse et d’Architecture des Systèmes (LAAS). He has worked on low frequency analog, digital and smart-power integrated circuits design, and is now involved in microwave circuits design methodologies on silicon technologies for telecommunication ICs. He currently works on digital design applied to high frequency synthesis (frequency dividers, phase/frequency detectors and direct digital synthesis (DDS)), and analog design using BAW devices. Thierry Parra was born in August 1964. He received the Ph.D. degree in electronics engineering and the accreditation to supervise research in 1991 and 1999, respectively, both from the Paul Sabatier University (UPS), Toulouse, France. He joined the LAAS-CNRS in 1991, and since 2002 he is Professor of electrical engineering. His research interests are currently on microwave components and new materials characterisation and modelling, and on optimisation and design of microwave integrated circuits, up to the millimeter wave frequency range.     

Validity of dietary recall over 20 years among California Seventh-day Adventists

Past dietary habits are etiologically important to incident disease. Yet the validity of such measurements from the previous 10-20 years is poorly understood. In this study, the authors correlated food frequency results that were obtained in 1994-1995 but pertained to recalled diet in 1974 with the weighted mean of five random 24-hour dietary recalls obtained by telephone in 1974. The subjects studied were 72 Seventh-day Adventists who lived within 30 miles of Loma Linda, California; had participated in a 1974 validation study; were still alive; and were willing to participate again in 1994. A method was developed to allow correction for random error in the reference data when these data had differentially weighted components. The results showed partially corrected correlation coefficients of greater than 0.30 for coffee, whole milk, eggs, chips, beef, fish, chicken, fruit, and legumes. Higher correlations on average were obtained when the food frequencies were scored simply 1-9, reflecting the nine frequency categories. The 95% confidence intervals for 15 of the 28 correlations excluded zero. Incorporation of portion size information was unhelpful. The authors concluded that in this population, data recalled from 20 years ago should be treated with caution but, for a number of important foods, that the degree of validity achieved approached that obtained when assessing current dietary habits.     

Comparison of two bowel preparations for colonoscopy: sodium picosulphate with magnesium citrate versus sulphate-free polyethylene glycol lavage solution

OBJECTIVES: Adequate preparation of the bowel is essential for accurate colonoscopic examination. We compared colonic preparation with sodium picosulphate plus magnesium citrate (SPS-Mg) with sulphate-free polyethylene glycol electrolyte lavage (PEG-EL) solution before colonoscopy, for quality of bowel cleansing, patient discomfort, and side effects. METHODS: Sixty-eight consecutive patients were randomly assigned to receive either 3 sachets of SPS-Mg (16.5 g each) (n = 39) or 3 L of PEG-EL (n = 29) on the day before colonoscopy. Shortly before the procedure each patient was interviewed to determine the degree of discomfort (1 = none or mild, 2 = moderate, 3 = severe) and side effects. The quality of bowel cleansing was graded by a gastroenterologist who was unaware of the method of preparation (from 1 = poor to 4 = excellent). RESULTS: Of the 29 PEG-EL patients, four (14%) did not complete the preparation because of side effects. The degree of discomfort was significantly greater with PEG-EL (mean score, 2.3 +/- 0.7) than with SPS-Mg (mean score, 1.4 +/- 0.5; p < 0.01). Nausea and vomiting were significantly more common in the PEG-EL group (38% vs 13%; p < 0.05). Using intention-to-treat analysis, bowel cleansing proved to be significantly better with SPS-Mg than with PEG-EL (mean score +/- SD, 3.05 +/- 0.9 and 2.57 +/- 1.0, respectively; p = 0.036). CONCLUSIONS: Colonic preparation with SPS-Mg is better tolerated, associated with significantly fewer side effects, and results in higher quality bowel cleansing than preparation with PEG-EL.     

Adhesives based on polyurethane graft multiblock copolymers: Tack,rheology and first morphological analyses

In this contribution, we report on the characterization of novel polyurethane graft-copolymers containing poly(n-butyl acrylate) side chains and, when extended, crystallizable polycaprolactone segments. Based on the previously reported synthesis, we attempt in the present work to correlate polymer structure and properties of segmented polyurethanes focussing on its potential interest as pressure-sensitive adhesive nanomaterial. For that purpose, thermomechanical analyses were coupled with complementary tack tests, rheology experiments and atomic force microscopy (AFM) imaging. Parameters such as relative hard and soft segments fraction or the introduction of crystallisable fragments that can play an important role on the adhesive comportment are described as well.     

Development and validation of a cross-section interface for PARCS

This paper deals with the development of a cross-section interface for PARCS and its validation. The interface is used to feed PARCS with material constants for Light Water Reactors. These material constants are obtained from a CASMO-4 library file and the SIMULATE-3 code is then used to read this library file. This interface allows a dependency of the material constants on exposure and on instantaneous and history variables. Since the functionalization of the cross-sections in CASMO-4/SIMULATE-3 is different from the one in PARCS, the conversion of the material data from the CASMO-4/SIMULATE-3 formalism to the PARCS formalism is not trivial. As a first check of the proper conversion of the data by the interface, the cross-section files created by the interface were read by PARCS. The data were thereafter edited for all possible burnup, instantaneous and history parameters and compared to the original data used to create the files. After this successful verification, a benchmark between PARCS and plant measured data was carried out. For this benchmark a number of measurement sets from the Swedish Ringhals-3 pressurized water reactor were obtained. These data were measured during different cycles and at different core exposures. The spatial distribution of the instantaneous variables, the history variables and the exposure were calculated by SIMULATE-3 and used by PARCS to retrieve the actual three-dimensional distribution of the material data. The deviation of the effective multiplication factor k_eff from criticality was found to be within ±200 pcm. Both the measured axial and radial power profiles were adequately reproduced by the PARCS simulations, although some discrepancies with plant data need to be further investigated.