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41.
Polycrystalline Fe7.5Al7Cr is a ferritic light weight steel that shows a strong anisotropic dissolution behaviour. This electrochemical phenomenon was investigated by use of a scanning droplet cell (SDC). The crystallographic orientation of the single grains was determined by electron back scatter diffraction (EBSD). The fraction of grains with a near 〈1 1 1〉 orientation (<10°) was 1.88 times higher than that of the near 〈0 0 1〉 orientation prior to annealing and 3.58 times higher after annealing. Voltammograms were performed on single grains with low index planes. The critical current density was 53% higher on 〈0 0 1〉 grains as compared to 〈1 1 1〉 grains. These results are used to discuss the electrochemical behaviour of the polycrystalline FeAlCr. 相似文献
42.
PE Verweij Z Erjavec W Sluiters W Goessens M Rozenberg-Arska YJ Debets-Ossenkopp HF Guiot JF Meis 《Canadian Metallurgical Quarterly》1998,36(6):1612-1616
The intra- and interlaboratory reproducibilities of a commercial sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of Aspergillus galactomannan in serum (Platelia Aspergillus; Sanofi Diagnostics Pasteur, Marnes-La-Coquette, France) were evaluated in six laboratories of university hospitals. Twenty serum samples were obtained from 12 neutropenic patients including 6 with invasive aspergillosis. These samples were blinded and sent to each center together with eight blinded ELISA-negative serum samples spiked with known concentrations of galactomannan. The centers were provided with ELISA microtiter plates from a single batch and a detailed protocol. Ten clinical samples showed ELISA reactivity, while 10 samples were ELISA negative. The mean coefficient of variation (CV) of the optical density values was 4.24% within a single assay and 25.6% between runs. The interassay CV of the ratios for the serum samples tested was 18.6%. Analysis of ordinal interpretation of the ELISA result (i.e., negative, gray zone, or positive) showed excellent reproducibility. Recalculation of the cutoff values for positive and negative samples suggested that the cutoff level recommended by the manufacturer could be lowered from 1.0 to 0.8 for negative samples and from 1.5 to 1.0 for positive samples. The intra- and interlaboratory reproducibilities were excellent when the ELISA results were interpreted as ordinal data, but considerable variation in optical density values and, to a lesser extent, in the ratios for the serum samples tested, was observed between runs. High assay variability was also found for serum samples spiked with known concentrations of galactomannan. Therefore, antigen titers in serum samples from a single patient, measured in different runs, should be compared with caution. 相似文献
43.
Subjects ranging in age from 50 to 89 years old, either with or without dementia were studied by both ELISA for anti-human T-cell lymphotropic virus type I (HTLV-I) gag 100-130 antibody and by cranial CT in order to clarify the relationship between HTLV-I infection and dementia. The frequency of anti-HTLV-I antibody was found to be significantly higher in the patients with dementia (24/130, 18.5%) than in those without dementia (11/139, 7.9%) (P=0.0169). Among the various types of dementia, HTLV-I seropositivity was found to be significantly associated with vascular dementia (11/48, 23%) (P=0.0087), but not with Alzheimer type dementia. In addition, HTLV-I seropositivity was also associated with Babinski sign, and the severity of cerebral infarction, ventricular dilatation and periventricular lucency on CT. The presence of HTLV-I therefore appears to be one of the risk factors for vascular dementia in HTLV-I endemic areas. 相似文献
44.
Agnes M Mwangwela Ralph D Waniska Cassandra McDonough Amanda Minnaar 《Journal of the science of food and agriculture》2007,87(3):399-410
Bechuana white cowpeas were micronised to three temperatures (130, 153 and 170 °C). Cooking properties of the cowpea seeds and the role of starch‐related properties were studied. In all cases, micronisation significantly reduced the cooking time and thus the time required for the cowpea seeds to attain a suitably soft texture. This was attributed in part to the significant improvement in rate of water absorption during cooking and starch pre‐gelatinisation, as evidenced by loss of birefringence and increased susceptibility of the cowpea starch to α‐amylase digestion. However, micronisation to 170 °C resulted in a severe deterioration in pasting properties of the cowpea flour, possibly due to starch depolymerisation and/or amylose‐associated crosslinking. Owing to these changes, cowpea seeds micronised to 170 °C required a longer cooking time than the other two micronised samples. Flour prepared from cowpea seeds micronised to 170 °C may have limited starch functionality. Copyright © 2006 Society of Chemical Industry 相似文献
45.
A Voss WJ Melchers P van den Hurk KA Bergman PE Verweij JF Meis 《Canadian Metallurgical Quarterly》1994,22(6):214-217
Between end December 1993 and end January 1994 a cluster of children infected/colonized with Enterobacter cloacae was seen in the neonatal intensive care unit of the University Hospital Nijmegen. The results of the epidemiological investigation are reported, which was aimed to differentiate between a random cluster of endogenously acquired Enterobacter strains and those possibly acquired exogenously via cross-infection. 5 isolates of the 7 patients were available for fingerprinting using interrepeat PCR. According to the fingerprint pattern, 4 of these isolates were identical, thereby suggesting cross-infection among the children. 3 neonates were colonized/infected with genotypically different isolates, suggesting that the infection/colonization developed endogenously. A control strain isolated from a patient at another ward showed the same genotype as the outbreak isolates. The transmission took probably place through one of the surgeons who, among all possible health care workers, were the only professional group treating patients in both units. 相似文献
46.
The principles for control of cracking in concrete structures due to imposed strain are investigated in this paper. The effects of uniform and non-uniform cooling and shrinkage are studied in medium-thick walls with regard to the amount of reinforcement necessary to distribute cracks. The influence of reinforcement on the behavior after the first crack is investigated, in particular its ability to reduce crack widths. The restraint force is significantly reduced for non-uniformly distributed imposed strain due to softening and cracking in the concrete. The amount of minimum reinforcement needed to distribute cracks is therefore significantly smaller for imposed strain in the form of drying shrinkage than for thermal imposed strain. Crack reinforcement is most effective for structures with large dimensions in the direction of external restraint. 相似文献
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50.
J Verweij HT Mouridsen OS Nielssen PJ Woll R Somers AT van Oosterom M Van Glabbeke T Tursz 《Canadian Metallurgical Quarterly》1995,20(3):193-201
In the present study effects of light on the sleep duration of anesthetized hornets (Vespa orientalis) were investigated. Following initial anesthesia by diethyl ether the sleeping time of workers and drones at 22 degrees C in the dark was 59 +/- 15 min. After repeated anesthesia the sleeping time was 30 +/- 15 min in the dark. When exposed to polychromatic light from a halogen lamp of 230 mW/cm2, focused on a spot of the cuticle of the hornet, the sleeping time was markedly shortened so that following initial as well as repeated anesthesia the hornets woke up after 4.5 +/- 2.9 min. Any decrease in light intensity resulted in an increase in the sleeping time but irradiances of less than 14 mW/cm2 had no measurable influence on the wake-up time. After illumination with polychromatic light from a mercury lamp the sleeping times were much shorter than after illumination with a halogen lamp at the same conditions and intensity. This difference is attributed to the relatively higher portion of U.V. light in the total emission of the Hg lamp. Effects of the spectral composition of the incident light beam on the wake-up of the sleeping hornets were also investigated. Near U.V. light in the 300-400 nm region was found to be most efficient. Shorter wavelengths as well as wavelengths between 400-470 nm had less influence and wavelengths above 470 nm had very little effect on the wake up. The sleeping times of hibernating queens were relatively longer than those of workers and drones under the same conditions. These effects are ascribed to the extraretinal light perception. The possible reasons underlying this phenomenon are discussed. 相似文献