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901.
Band-gap tailoring of ZnO by means of heavy Al doping 总被引:1,自引:0,他引:1
BE Sernelius K Berggren Z Jin I Hamberg CG Granqvist 《Canadian Metallurgical Quarterly》1988,37(17):10244-10248
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In 15 caries-active patients, with a total of 770 exposed root surfaces, the effect of fluoride therapy and professional tooth cleaning was studied during a 1-year period. Dental plaque from 92 of the root surfaces and whole saliva samples were analysed at baseline and after 12 months for the presence of specific bacteria. The results showed that the number of active carious lesions had decreased from 99 to 46, while the inactive lesions had increased from 69 to 124. Of the active lesions which had been converted into inactive lesions, most were on the buccal and fewest were located on the distal surfaces. Lower plaque scores were found on sound and inactive root surfaces compared to active surfaces. The salivary concentrations of mutans streptococci and lactobacilli remained constant during the 12-month observation period. There was a tendency for higher levels of Streptococcus mutans in plaque from active lesions compared with sound root surfaces, whereas an inverse relationship was noted for the Streptococcus oralis group. No significant differences in the Actinomyces naeslundii counts were detected. In conclusion, the 12-month prophylactic programme had an effect on the clinical surface characteristics of root caries, but the components of the oral microflora selected for study seemed to be relatively unaffected during the observation period. 相似文献
905.
SB Ahmaidi AL Varray AM Savy-Pacaux CG Prefaut 《Canadian Metallurgical Quarterly》1993,103(4):1135-1141
PURPOSE: The purpose of this study was to assess the validity of the 20-m shuttle test with 1-min stages (20-MST) to estimate maximal oxygen uptake (VO2 max) and its ability to register cardiorespiratory modifications over the course of an individualized aerobic training program for mild to moderately asthmatic children acclimatized to moderate altitude. METHODS: Forty-eight asthmatic subjects aged 12 to 17 years performed both a maximal incremental exercise test on a cycle ergometer and the 20-MST. Ten of the subjects were then randomly chosen and trained three times per week at their ventilatory threshold (Vth) intensity level for three months. Another group of ten asthmatic subjects served as control subjects. Training intensity was adjusted monthly; heart rate values at Vth were increased by the same proportion as the increase in Vo2 max as measured by the 20-MST. At the end of training, both groups were again evaluated with the two tests. The Vo2 max values by direct measurement and by the 20-MST were not significantly different for the entire population (46.5 +/- 1.6 vs 47.2 +/- 2.1 ml.min-1.kg-1). In addition, the two test results were in close agreement (r = 0.84; p < 0.01). After training, a sharp improvement in the direct Vo2 max (44.1 +/- 2.4 to 51.2 +/- 1.9 ml.min-1.kg-1) was noted in the training group as well as an increase in the Vth (25.6 +/- 1.9 to 32.1 +/- 3.4 ml.min-1.kg-1), the maximal power (152 +/- 7.1 to 185 +/- 3.8 W), and the maximal oxygen pulse (0.24 +/- 0.007 to 0.27 +/- 0.008 ml.beat-1.kg-1). CONCLUSION: The indirect measure confirmed these results: a simultaneous increase in VO2 max (43.7 +/- 2.5 to 53.8 +/- 2.1 ml.min-1.kg-1), maximal oxygen pulse (0.22 +/- 0.004 to 0.27 +/- 0.006 ml.beat-1.kg-1), and the number of stages completed (7 +/- 1.4 to 10.1 +/- 1.3) was observed. It was concluded that the 20-MST has sufficient validity to assess VO2 max and to register cardiorespiratory modifications over the course of individualized aerobic training programs in mild and moderately asthmatic children. It thus may be used to adjust training intensities during these programs. 相似文献
906.
DG Armstrong G Baxter CG Gutierrez CO Hogg AL Glazyrin BK Campbell TA Bramley R Webb 《Canadian Metallurgical Quarterly》1998,139(4):2146-2154
This work is concerned with the role of insulin-like growth factor binding protein (IGFBP)-2 and -4 in the regulation of IGF bioactivity in bovine follicles during the development of dominance. We measured the expression of IGFBP-2 and -4 messenger RNA (mRNA) in small (1-4 mm) gonadotropin-sensitive follicles and medium (4-8 mm) and large (>8 mm) gonadotropin-dependent follicles using in situ hybridization. In healthy nonatretic bovine follicles, IGFBP-2 and -4 mRNA expression was confined to granulosa and theca tissue, respectively. Moreover, during the development of follicular atresia, there were distinct changes in the temporal and spatial expression of these genes. IGFBP-2 immunoactivity was localized in granulosa tissue and the basement membrane of healthy preantral follicles, whereas IGFBP-4 immunoactivity was localized in both theca and granulosa tissue. Of particular interest was the lack of IGFBP-2 mRNA expression in large (>8 mm) gonadotropin-dependent follicles, an observation that was confirmed by the lack of immunoreactive IGFBP-2 in these follicles. The regulation of IGFBP-2 and -4 mRNA expression in granulosa and theca cells was analyzed using a serum-free cell culture system. FSH inhibited the expression of IGFBP-2 mRNA in granulosa cells, whereas LH stimulated IGFBP-4 mRNA expression in theca cells. Our results provide evidence for the existence of different roles for IGFBP-2 and -4 in the developing follicle. 相似文献
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Dendritic cells (DC) are professional antigen presenting cells, playing an important role in the initiation of T- and T cell dependent immune responses. DC are highly mobile cells and the sequential migration of DC in and out of tissues is accompanied by phenotypical as well as functional changes instrumental to their function as sentinels of the immune system. Herein, we will review recent progress in understanding the origin of DC, their migratory behaviour and their capacity to attract and interact with lymphocytes, with emphasis on the chemokine system. 相似文献
909.
Impairment in list learning is considered a primary symptom of Alzheimer's disease (AD), yet there are no published reports examining the relationship between list learning and severity of cognitive impairment. We gave nine-item and 16-item versions of the California Verbal Learning Test (CVLT; Delis et al., 1987), a standardized shopping list assessment of memory, to 24 AD patients (mean age = 76.2 +/- 8.1; mean years of education = 13.8 +/- 2.4), who were stratified into four groups based on MMSE scores (mean = 16.0 +/- 5.6). ANOVAs revealed severity effects for total list learning (p < 0.001), the first trial (p < 0.001), the last trial (p < 0.001) and short- and long-delay recall measures. Most of these differences seemed due to floor effects. For example, the modal number of words recalled after a delay was 0 by subjects with MMSE scores below 21. Severity of cognitive impairment was associated with the proportion of intrusions such that the most severely demented subjects gave almost entirely intrusion responses. Surprisingly, list length did not significantly affect any of the free recall measures. Our results suggest that list learning and recall seem to be lost relatively early in AD. Measures of list recall like the CVLT may not be useful in tracking severity of cognitive impairment over time. 相似文献
910.