Determination of several elements in duplicate meals from catering establishments using closed vessel microwave digestion with inductively coupled plasma mass spectrometry detection: estimation of daily dietary intake

An estimation of the dietary exposure of French consumers to 21 essential and non-essential mineral elements using duplicate meals (breakfast and lunch) purchased from catering establishments was investigated after digestion by a closed vessel microwave procedure and quantification by ICP-MS. Daily dietary exposure estimates for metals and minerals were compared with the Provisional Tolerable Weekly Intakes (PTWI), the Tolerable Daily Intake (TDI) or the Acceptable Daily Intakes (ADI), as established by the FAO/WHO to estimate the risk of toxicity, and the US Recommended Daily Allowances (US RDA) or the Estimate Safe & Adequate Daily Dietary Intakes (ESADDI). Moreover, comparisons were made with those from previous French studies as well as those from other countries. The estimated mean daily intakes were 11 μg for lithium, 3.42 g for sodium, 192 mg for magnesium, 2.03 mg for aluminium, 3.64 g for potassium, 642 mg for calcium, 154 μg for chromium, 12.3 mg for iron, 2.15 mg for manganese, 4 μg for cobalt, 74 μg for nickel, 925 μg for copper, 10.2 mg for zinc, 147 μg for arsenic, 66 μg for selenium, 112 μg for molybdenum, 3.6 μg for cadmium, 2.32 mg for tin, 3 μg for antimony, 9 μg for mercury and 34 μg for lead. For the non-essential (toxic) elements, aluminium, tin, antimony, cadmium, arsenic, mercury and lead, the daily intake estimates were far below tolerable limits; and similar or somewhat lower than their respective PTWI, ADI, TDI, ESADDI and US RDA for individual minerals and essential trace elements, with good agreement with other country studies. The performance of the multi-elemental ICP-MS technique was also evaluated.     

Enhanced performance of a bolometric detector at mK temperatures in high magnetic fields

Results on the operation of a bolometer detector in high magnetic fields and at very low temperatures are presented. We tested a diamond absorber on a Ge thermistor in magnetic fields up to 8 Tesla and temperatures down to 10 mK using an⁵⁵Fe X-ray and¹⁰⁹Cd electron source. Heavily doped Ge shows a giant magnetoresistance effect. This was used to tune the thermistor impedance to an optimal value.     

Pulsed photoacoustic spectroscopy applied to the diffusion of sunscreen chromophores in human skin: the weakly absorbent regime

Pulsed photoacoustic spectroscopy was used to study the penetration of sunscreen chromophores into human skin. This study focuses on basic solutions containing single typical filter molecules, as used in current sunscreens, dissolved in mineral oil. The pulsed form of the photoacoustic technique was preferred because it provides more detailed information on the filter distribution within the different layers of human skin. A new methodology provides better insight into the diffusion process through signal analysis in the time and frequency domains, allowing for global and depth-related characterization. The penetration of the chromophore influences the response signal by inducing changes in the optical and thermal properties at different depths within the medium. The light scattering effect of titanium dioxide was demonstrated by the same technique.     

Reproducibility and validity of a food-frequency questionnaire designed for use in girls age 7 to 12 years

This study focused on a food-frequency questionnaire (FFQ) designed to measure nutrient intake in girls aged 7 to 12 years, inclusive. The instrument's reproducibility and validity were assessed using food records (FRs) as gold standards of measurement. Log-transformed nutrient intake estimates were compared from two FFQs and between FFQs and FRs. Intraclass correlation coefficients measuring the reproducibility of the FFQ ranged from 0.11 (starch) to 0.69 (fiber). Intraclass correlation coefficients measuring agreement between FFQ and 14l-day FR data varied between 0.15 (starch) and 0.68 (vitamin B2) for the first, and between 0.06 (starch) and 0.95 (vitamin B1) for the second FFQ. FFQs were in the best agreement with FRs for the following nutrients: fiber, vitamin B1, vitamin B2, vitamin C, and beta-carotene. Joint classifications revealed that overall, 36% of subjects were similarly categorized by FFQ and FR, and 70% of those in the lowest or highest FR quartiles were were found in the lowest or highest FR quartiles were found in the lowest or highest two FFQ quartiles, respectively.     

Visualization of artificial lignin supramolecular structures

In this paper we are presenting the results of our environmental scanning electron microscopy (ESEM) investigation of the lignin model compound--enzymatically polymerized coniferyl alcohol, also known as dehydrogenate polymer (DHP). The goals of this study were to visualize the supramolecular organization of DHP polymer on various substrates, namely graphite, mica, and glass, and to explore the influence of substrate surface properties and associated collective phenomena on the lignin self-assembled supramolecular structure. Based on results obtained with ESEM, combined with previously published results based on scanning tunneling microscopy (STM) and electron spin resonance (ESR) technique, we looked at lignin structure ranging from a monomer on a fraction of nanometer scale to a large aggregate on a fraction of millimeter scale, therefore using six orders of magnitude range of size. Herein, we are presenting evidence that there are at least four different levels of the supramolecular structure of lignin, and that its supramolecular organization is well dependent on the substrate surface characteristics, such as hydrophobicity, delocalized orbitals, and surface-free energy.     

Monolithic InP-based grating spectrometer for wavelength-division multiplexed systems at 1.5 mu m

A monolithic InP-based grating spectrometer for use in wavelength-division multiplexed systems at 1.5 mu m is reported. The spectrometer uses a single etched reflective focusing diffraction grating and resolves >50 channels at 1 nm spacing with a approximately 0.3 nm channel width and at least 19 dB channel isolation. Operation is essentially of the state of the input polarisation.<>     

Relationship between formal thought disorder and retardation in schizophrenia.

17 schizophrenics admitted into the hospital less than 6 mo before were compared on Bannister's Grid Test of Schizophrenic Thought Disorder with 19 schizophrenics admitted over 6 mo before and with a group of 17 nonschizophrenic, psychiatric controls under 3 conditions: fast rate of responding, slow rate of responding, and in-between rate of responding. It was predicted that the schizophrenics would show more thought disorder under fast than slow conditions and that the recently admitted schizophrenics would be more thought disordered than the earlier admitted schizophrenics. Contrary to expectations, the patients tended to show less thought disorder on the test when their responses were speeded than when they were encouraged to take their time. Moreover, the earlier admitted schizophrenics showed more thought disorder than the recently admitted schizophrenics under all 3 conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experience with an undergraduate level CAI-course for electronic engineers in industry

An experiment has been performed with the application of a CAI course on four terminal networks for engineers working in the development department of an electronics firm.Evaluation data have been collected. Students as well as their department head indicate general satisfaction with their achievements: interaction with the computer and the freedom to study on a convenient time schedule was rated especially highly.In the paper the CAI method selected and the goal set for the development of the course are discussed. A test group on which objective measurements were made allowed for a revision of the course content. The general observations and personal opinions of the test subjects are compared with those of the students.     

Effects of postpartum uterine diseases on milk production and culling in dairy cows

The objective was to quantify the effect of postpartum uterine diseases on milk production and culling. Data from 2,178 Holstein cows in 6 herds enrolled in a randomized clinical trial were used. Milk production data from the first 4 Dairy Herd Improvement Association (DHIA) test-days and culling data from farm records were collected. Retained placenta (RP; ≥24 h after parturition) and metritis [≤20 d in milk (DIM)] were diagnosed by farm managers using standardized definitions. Farms were visited weekly and cows were examined at 35 and 56 (±3) DIM using endometrial cytology (cytobrush device), vaginal discharge scoring (Metricheck device), and measurement of cervical diameter by transrectal palpation. Diagnostic criteria for cytological endometritis (CYTO) and purulent vaginal discharge (PVD) were established based on a detrimental effect on subsequent reproduction. Statistical analyses were performed using linear mixed models, logistic regression models, and Cox proportional hazard models, accounting for the effects of experimental treatments and herd clustering. Milk production and culling were the outcomes. Primiparous and multiparous cows were modeled separately for milk production. Milk production of primiparous cows was unaffected by uterine diseases. The effect of metritis on milk production was variable over time in multiparous cows: it decreased production per cow by 3.7 kg at the first DHIA test, but was not different at later tests. Retained placenta decreased milk production by 2.6 kg/d in multiparous cows through the first 4 DHIA tests. The projected effects of metritis and RP in multiparous cows were reductions of 259 kg and 753 kg over 305 DIM, respectively; these effects were additive. Neither CYTO nor PVD affected milk production. Culling risks at 30 and 63 DIM were unaffected by RP and metritis. Culling hazard up to 300 DIM was unaffected by RP, metritis, CYTO, or PVD, whether or not pregnancy status, milk production, and displaced abomasum were accounted for. Uterine disease decreased pregnancy rate, which was a substantial risk factor for culling; however, if affected cows became pregnant they were not at greater risk of culling.     

Characterizing gum natural rubber samples through advanced techniques

Owing to its origin, Natural Rubber exhibits more variation than synthetic polymers. If, over the years, NR specifications have evolved from mere visual inspections towards the more complex Technically Specified Rubber (TSR) schema, industrial practice shows that, even for typical TSR grades, significant variations still exist within each shipment, especially in regard to processability. It follows that mastication is quite systematically needed in industrial operations, without or with processing aids or so‐called peptizers. Typical NR compounding operations consume therefore time and mixer capacity, a situation, which obviously calls both better characterization methods of (gum) natural rubber and eventually improved grades. There are nowadays promising new techniques to analyze and characterize polymer materials, some of which are a priori attractive for a better specification of NR grades. One such technique is the so‐called Fourier Transform rheometry, a dynamic testing method to investigate both the linear and the non‐linear viscoelastic domains of polymer materials. Other are spectroscopic methods like solid Nuclear Magnetic Resonance (NMR), either liquid or solid, whose results might be complemented by Size Exclusion Chromatography with special detection techniques, e.g. SEC‐MALS, and Differential Scanning Calorimetry (DSC). The purpose of the work reported here was to investigate a series of gum NR grades using such techniques, with the objectives not only to demonstrate their interest but also to cross‐validate their results. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011