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排序方式: 共有837条查询结果,搜索用时 15 毫秒
831.
Chronic staphylococcal osteomyelitis: an experimental model. 总被引:1,自引:0,他引:1
832.
Peter H. Becker Christian C. Voigt Jennifer M. Arnold Rolf Nagel 《Journal of Ornithology》2006,147(1):115-118
We describe a non-invasive technique to obtain blood samples from incubating birds without trapping and handling. A larval
instar of the blood-sucking bug Dipetalogaster maximus (Heteroptera) was put in a hollowed artificial egg which was placed in a common tern (Sterna hirundo) nest. A gauze-covered hole in the egg allowed the bug to draw blood from the brood patch of breeding adults. We successfully
collected 68 blood samples of sufficient amount (median=187 μl). The daily success rate was highest during the early breeding
season and averaged 34% for all trials. We could not detect any visible response by the incubating bird to the sting of the
bug. This technique allows for non-invasive blood collection from bird species of various sizes without disturbance. 相似文献
833.
The mobilization of dust (i.e., detachment and removal of dust grains from a substrate) and the exfoliation of a film of erosion
products in tokamaks have been studied theoretically. The following mechanisms of dust mobilization have been taken into account:
(i) sharp heating (thermal shock) as a result of, e.g., plasma disruption and edge instabilities; (ii) substrate vibrations;
and (iii) gas and plasma flow (wind) action. The most effective mobilization takes place under the action of sharp heating.
Power fluxes that are characteristic of edge instabilities can mobilize dust grains with dimensions within or even greater
than 0.1–1 μm. The velocities of detached grains reach ν ∼ 100 m/s for heavy grains and up to ν ∼ 300 m/s for the light ones. Conditions favoring the exfoliation of a film of erosion
products are determined. It is shown that exfoliation under the action of edge instabilities can take place at a film thickness
of h > 1 μm. Under the action of thermal-shock-induced stresses, the exfoliated film flakes with a size ranging from fractions
of a millimeter to several centimeters break into pieces. 相似文献
834.
C M Lucas M G Havenith F H van der Veen J Habets T van der Nagel J M Schrijvers-Van Schendel O C Penn H J Wellens 《Journal of applied physiology》1992,72(3):828-835
To study functional, structural, and biochemical adaptations to electrical stimulation of striated muscle in a large animal, the canine latissimus dorsi (LD) muscle was conditioned continuously for 24 wk with an increasing number of pulse bursts (burst duration 250 ms, burst frequency 30 Hz). Force measurements in vivo after 12 wk showed a significant decrease in the ripple, the ratio of interstimulus to peak force amplitude, from 0.94 +/- 0.03 to 0.13 +/- 0.08 (SE; n = 8, P less than 0.05), indicating reduction in contractile speed. Also the steep part of the force-frequency relation shifted to lower frequencies. A significant change in fiber-type composition was seen with both enzyme- and immunohistochemistry, manifested by an increase of type I fibers from 29.5 +/- 2.9 to 83 +/- 8% (SE; n = 8, P less than 0.05). During this period a transient rise in the number of type IIc/Ic fibers (from 3 to 10%) was seen. In the stimulated muscle, capillary-to-fiber ratio increased from 1.9 +/- 0.4 to 2.7 +/- 0.1 (P less than 0.05). A significant increase in mitochondrial volume was also seen, especially in the peripheral part of the fiber. Both creatine kinase and lactate dehydrogenase revealed a significant decline in activity within 12 wk. At the same time a shift in lactate dehydrogenase-isozyme pattern was observed toward the cardiac composition. No additional changes occurred after 12 wk of stimulation, indicating that conversion of the canine LD muscle was complete within this period. 相似文献
835.
Manuela Nagel Ahmad M. Alqudah Marlne Bailly Loïc Rajjou Sibylle Pistrick Gabriele Matzig Andreas Brner Ilse Kranner 《Plant, cell & environment》2019,42(4):1318-1327
Barley is used for food and feed, and brewing. Nondormant seeds are required for malting, but the lack of dormancy can lead to preharvest sprouting (PHS), which is also undesired. Here, we report several new loci that modulate barley seed dormancy and PHS. Using genome‐wide association mapping of 184 spring barley genotypes, we identified four new, highly significant associations on chromosomes 1H, 3H, and 5H previously not associated with barley seed dormancy or PHS. A total of 71 responsible genes were found mostly related to flowering time and hormone signalling. A homolog of the well‐known Arabidopsis Delay of Germination 1 (DOG1) gene was annotated on the barley chromosome 3H. Unexpectedly, DOG1 appears to play only a minor role in barley seed dormancy. However, the gibberellin oxidase gene HvGA20ox1 contributed to dormancy alleviation, and another seven important loci changed significantly during after‐ripening. Furthermore, nitric oxide release correlated negatively with dormancy and shared 27 associations. Origin and growth environment affected seed dormancy and PHS more than did agronomic traits. Days to anthesis and maturity were shorter when seeds were produced under drier conditions, seeds were less dormant, and PHS increased, with a heritability of 0.57–0.80. The results are expected to be useful for crop improvement. 相似文献
836.
K Bender S Bissbort H Crone H Senff A Steiert H Neumann M Koch M Nagel T F Wienker 《Human heredity》1988,38(1):12-17
Linkage analyses of locus pairs involving IGK, JK, CO, KEL and AHCY resulted in altogether negative lod scores, thereby dwindling the reported linkage relations. 相似文献
837.
L. Brüggemann S. Sommer E. Fiedler. K. Karbaum C. Albrecht R. Hedlich B. Nagel 《Engineering in Life Science》1990,10(1):79-84
The aim of the project BD1 (Biotechnology Data Bank 1) is to improve the data processing for research in biotechnology. In BD1, data of several classes of objects and methods are compiled. A data file conception consisting of object data files, method data files and feature data files was created, which can be easily extended to further classes, and which allows the combination of different classes of features to the same class of objects. There are two main approaches to use BD1: 1. making available informations on certain biotechnological objects, 2. the identification of unknown objects by means of their feature pattern. The microbiological data base and the possibilities of data base search are presented by example of lactic acid bacteria. 相似文献