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排序方式: 共有271条查询结果,搜索用时 15 毫秒
61.
Grains of two regular and two waxy barley cultivars were milled into break and reduction stream flours using a wheat milling mill, granulated to facilitate feeding and flow through the barrel, and extruded to form expanded products using a modified laboratory single‐screw extruder. As moisture content of barley granules decreased from 21 to 17%, the expansion index of extrudates increased from 1.81 to 2.68, while apparent modulus of compression work (AMCW) decreased from 17.1 × 104 to 7.8 × 104 N/m2. Break stream flours of both regular and waxy barley produced extrudates with higher expansion index (2.72–3.02), higher water absorption index (WAI), and lower AMCW than extrudates from reduction stream flours. Extrudates produced from regular barley had generally higher expansion and lower density than those produced from waxy barley. The specific mechanical energy (SME) was greater during extrusion of regular than of waxy barley. Barrel temperatures of 130, 150, and 170°C for the feeding, compression, and metering sections, respectively, resulted in higher SME, higher expansion index, lower water absorption index and lower AMCW of extrudates compared with a constant extruder barrel temperature of 160°C. Increased screw speed generally resulted in larger expansion index and increased WAI of extrudates. With increased feed rate from 89 to 96 g/min, the expansion index of extrudates decreased from 3.20 to 2.78 in regular barley and 3.23 to 2.72 in waxy barley, and harder extrudates were produced. 相似文献
62.
Lauren V Powers 《Veterinary Clinics of North America: Exotic Animal Practice》2006,9(2):287-302, vi
General techniques performed on psittacine birds are described in this article, including restraint, handling, and grooming. Procedures to collect diagnostic samples and to administer therapeutic agents are detailed, including fluid therapy and nutritional support. 相似文献
63.
K. Finora N. F. Leibman M. J. Fettman B. E. Powers T. A. Hackett S. J. Withrow 《Veterinary and comparative oncology》2006,4(3):178-183
Staging of dogs with cutaneous mast cell tumours (MCTs) is an important diagnostic step. Aspiration of the liver and the spleen is often part of routine staging. This study cytologically compared mast cell numbers in fine‐needle aspirates of liver and spleen of clinically normal unaffected dogs with those of dogs with cutaneous MCT and an ultrasonographically normal appearing liver and spleen. The unaffected dogs (n = 32) were selected from humane society dogs, and the affected dogs (n = 51) were selected from hospital cases. There were no statistically significant differences in each of the parameters evaluated for the liver aspirates. For splenic aspirates, affected dogs showed significantly more mast cells per cluster (P = 0.04) and more isolated mast cells per slide (P = 0.03) compared with unaffected dogs. However, no clinically important difference existed between the unaffected and affected dogs; thus, routine aspiration of an ultrasonographically normal appearing liver and spleen of dogs with cutaneous MCT does not appear to be a clinically useful staging tool. 相似文献
64.
Mehl ML Withrow SJ Seguin B Powers BE Dernell WS Pardo AD Rosenthal RC Dolginow SZ Park RD 《Journal of the American Veterinary Medical Association》2001,219(5):614-617
Spontaneous regression of primary malignant bone tumors is rare but has been reported in the human literature. To the authors' knowledge, spontaneous regression of primary bone tumors in dogs or cats has not been reported. Osteosarcoma (OSA) is the most common primary bone tumor in humans, and it has been reported that the incidence of OSA is 40 to 50 times greater in dogs than humans. In this report, high-grade OSA was diagnosed in biopsy specimens obtained from 4 dogs that subsequently underwent spontaneous regression without tumor-specific treatment. Osteosarcoma in dogs has characteristics similar to that of OSA in humans. 相似文献
65.
66.
67.
Powers EB 《Science (New York, N.Y.)》1943,97(2515):242-243
68.
Hemoglobin adaptation for fast and slow water habitats in sympatric catostomid fishes 总被引:1,自引:0,他引:1
D A Powers 《Science (New York, N.Y.)》1972,177(46):360-362
The oxygen equilibria of Catostomus insignis hemoglobins are pH dependent. Catostomus clarkii hemoglobins have some components (20 percent) whose oxygen equilibria are independent of pH because the alpha chains have NH(2)-termini that are blocked and the beta chains lack the "usual" COOH-terminal histidine. Since the Bohr effect is normally a beneficial phenomenon, the maintenance of some hemoglobins without a Bohr effect must provide a physiological advantage that is habitat specific. The intrastream ecological preferences of these sympatric catostomids suggest that the hemoglobins without the Bohr effect confer an ecological advantage in a swift water habitat. 相似文献
69.
70.
Kaeberlein M Powers RW Steffen KK Westman EA Hu D Dang N Kerr EO Kirkland KT Fields S Kennedy BK 《Science (New York, N.Y.)》2005,310(5751):1193-1196
Calorie restriction increases life span in many organisms, including the budding yeast Saccharomyces cerevisiae. From a large-scale analysis of 564 single-gene-deletion strains of yeast, we identified 10 gene deletions that increase replicative life span. Six of these correspond to genes encoding components of the nutrient-responsive TOR and Sch9 pathways. Calorie restriction of tor1D or sch9D cells failed to further increase life span and, like calorie restriction, deletion of either SCH9 or TOR1 increased life span independent of the Sir2 histone deacetylase. We propose that the TOR and Sch9 kinases define a primary conduit through which excess nutrient intake limits longevity in yeast. 相似文献