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951.
U Della Casa M Picchio U Passaro A Lombardi G Ramacciato PM Amodio A Paolini 《Canadian Metallurgical Quarterly》1997,52(6):705-712
Resistance to benzalkonium chloride (BC) among Pseudomonas spp. isolated from poultry carcasses was determined and strategies for elimination of resistant strains evaluated. This investigation showed that resistance was quite common, about 30% of the isolates being able to grow in 200 micrograms ml-1 BC. Pseudomonas fluorescens strains were generally less susceptible than strains of Ps. lundensis and Ps. fragi. An overnight incubation in medium containing 200 micrograms ml-1 BC was sufficient to reduce the susceptibility of two Pseudomonas strains to the lethal effect of BC significantly. Adding EDTA enhanced the lethal effect of BC, but the effect was reduced after growing cells in medium containing BC and EDTA. Growth in medium with a quaternary ammonium compound (QAC) rendered the cells more susceptible to chlorine, phenolics, and alkylaminoacetate. These results indicate that alternating use of QACs with these compounds can be used to avoid build-up of resistant strains. In addition, increased temperatures improved the lethal effect of BC and should be considered when planning disinfection routines. 相似文献
952.
Fetal cells that circulate in maternal peripheral blood (PB) during pregnancy offer a potential source of nucleated fetal material for noninvasive prenatal diagnosis. Fluorescence-activated cell sorting was used to target two populations of fetal cells: nucleated erythroid cells (NECs; CD71/glycophorin-A+ CD45(lo-int) CD34-) and hematopoietic progenitor cells (CD34+ cells; CD34++ CD71/glycophorin-A- CD45(int)). Fetal cells were detected by fluorescence in situ hybridization (FISH) using directly conjugated chromosome X and Y probes in 65% (13 of 20) of the maternal PBs (fetal karyotype 46,XY). The frequency of fetal cells isolated from the NEC and CD34+ fractions was, respectively, 0 to 14 and 0 to 7 cells per 2 x 10(7) previously frozen maternal cells (approximately 20 mL of blood). In nonfrozen samples, the yield and recovery of fetal cells was moderately improved. Culturing the CD34+ sorted fractions in serum-free media with cytokines improved the quality of the FISH preparations and resulted in a slight expansion in detectable fetal cells. The frequency of fetal cells isolated from cultured CD34+ fractions was 0 to 35 and 0 to 93 cells per 2 x 10(7) previously frozen and nonfrozen maternal PB cells, respectively. These results document the isolation, characterization, and enumeration of fetal cells from the maternal periphery that appear to be present in most, but not all, samples analyzed. 相似文献
953.
954.
JJ Dubec PL Munk JX O'Connell MJ Lee D Janzen D Connell B Masri PM Logan 《Canadian Metallurgical Quarterly》1997,26(12):732-736
Extraskeletal osteosarcomas are rare tumors, and the telangiectatic variety is the least common histological variety in this group. This report describes the clinical and MR imaging findings in two cases arising in the pretibial soft tissues. Both tumors demonstrated marked inhomogeneity with T2-weighted spin echo and STIR sequences. One of the tumors revealed numerous fluid levels within the lesion. A review of the MRI features of these tumors is provided. Osteosarcoma with telangiectatic features should be considered in the differential diagnosis of a soft tissue mass with fluid-fluid levels in patients 40 years of age or older. 相似文献
955.
M. Céu Viana Luís C. Oliveira Ana I. Mata 《International Journal of Speech Technology》2003,6(1):83-94
This paper describes a set of experiments aiming at the construction and evaluation of a new phrasing module for European Portuguese text-to-speech synthesis, using classification and regression trees learned from hand-labelled texts. Using the assessment criteria of matching boundary predictions against the corresponding labelled ones, the best solution achieves an overall performance of 91.9%, with 86.3% of correctly assigned breaks and 4.3% of false insertions. Although in absolute terms such scores may be considered surprisingly good given the size of the training set, the total number of exact matches at the sentence level is much lower (22%). This suggested a more formal experiment to test the acceptability of the predicted phrasing in the judgement of human evaluators. As the model was not trained on a labelled speech corpus but on hand-labelled texts, the reference phrasing needed also to be assessed. The evaluation experiment involved 90 participants who were asked to grade both the automatic and the reference phrasings, and also to express their opinion on where the breaks should be placed. As expected, the results showed a large variability among the subjects in their acceptance of a specific sentence partition, and criteria had to be defined to summarise the data from the different evaluators. With the adopted criteria, the performance of the automatic assignment procedure at the sentence level is better rated by human evaluators than by simple matching with the reference corpus (78% vs. 22%, respectively). 相似文献
956.
957.
The purpose of this study was to investigate the effects of waterbeds on heart rate (HR) in preterm infants. Subjects were 22 medically stable preterm infants. Across a 10-day study, HR was determined for a 1-hour period on each day. Baseline HRs with infants on the standard incubator mattress were obtained on the first 2 days of the study. They were then placed on the waterbed for 4 days. They were then returned to the incubator mattress and studied for 4 more days. Infants served as their own controls among baseline, on-waterbed (On-WB) and off-waterbed (Off-WB) periods. HR was determined by using a heart beat counting feature of the neonatal cardio-respiratory monitors. Analysis of variance revealed significant HR variability among subjects. There was no difference between baseline HR and on-waterbed HR. The HR increased when infants were transferred back to the standard mattress. The possibility that theophylline acted as a confound existed because doses were changed and levels varied for some subjects within the study period. Eight infants responded to the waterbed with lower HR during the On-WB period compared to the baseline (mean reduction = 5.7 bpm). The findings that HRs rose when the infants were returned to the incubator mattress are similar to those of a previous study. The subjects' reactivity to changes in treatment condition continues to confound the question as to whether waterbed therapy effects a reduction in HR. Since waterbeds have consistently resulted in soothing effects such as improved sleep and lowered activity, failure to produce a concomitant reduction in HR warrants attention toward other factors that may be determinants of heart rate. The high variability within and among subjects raises questions as to the usefulness of the HR variable for determining energy costs. 相似文献
958.
959.
Y. M. Aravot Lelia Arcan M. E. Arcan Ana Albu-Yaron 《Journal of Materials Science》1990,25(8):3714-3722
Measurement of the adhesion toughness of a fast cure thermosetting powder coating used for corrosion protection of cold-rolled steel has been attempted in a shear test under uniform plane stress loading conditions at the interface. A specially designed test specimen preparation procedure (by direct crosslinking) and geometry (symmetrical) was developed to enable proper mechanical behaviour under shear initiation of fracture and uniform plane stress loading in the significant section of the specimen — the interface. The shear test was designed to measure the nominal and the net ultimate shear stress values (USS)n and (USS)net' as well as the critical stress intensity factor (SIF) of interfaces. From experimentally measured critical load at which the adhesion failed, the ultimate shear stress values (USSnet N mm–2) were calculated and used as a quantitative information of the bond toughness along the interfaces. The experimental results with a range of specimens revealed that the test can, indeed, discern subtle variations influencing adhesion such as type of cold-rolled steel, an iron phosphate pretreatment before coating or variation in stoving temperatures. Fractographic analysis of shear failed specimens on mating surfaces revealed generation of a microcrack network in most of the fracture pattern tested, indicating fracture mechanism transitions characteristic of pure shear for both iron phosphated free cold-rolled steel-lacquer (SL) as well as for iron phosphated cold-rolled steel-lacquer (SPL) specimens. The fractographs, however, indicate fracture propagation more difficult for SPL specimens and comparatively smooth fracture surface for SL specimens, obviously affected by variations in their respective interface structure and morphology. This behaviour correlates well with measurements of (USS)net in test. 相似文献
960.
Mrcio Cornlio Ana Cavalcanti Augusto Sampaio 《Electronic Notes in Theoretical Computer Science》2002,70(3):311-330
In this paper we present how refactoring of object-oriented programs can be accomplished by using refinement. Our approach is based on algebraic laws of an object-oriented language for refinement similar to Java. We follow a strategy involving data and algorithmic refinement of classes. 相似文献