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951.
The effects of mechanical injury on the skin, connective tissue, muscle and bone of the goldfish is described 28 days following the injury. There is evidence of a dynamic response but the apparent inability of muscle regeneration to any degree is noted. 相似文献
952.
953.
Pressure-flow relationships in the isolated canine trachea 总被引:1,自引:0,他引:1
954.
Phenylacetic, 3-phenylpropionic, -hydroxyphenylacetic and 3 (-hydroxyphenyl) propionic acids together with the series of C2 to C6 saturated fatty acids previously reported in the anal sac secretion of the red fox () are identified as constituents of the anal sac secretion of the lion (Panthera leo). All these compounds are also observed in the anal sac secretion of the red fox using gas chromatography. The aerobic microflora of red fox and domestic dog () anal sac secretion samples invariably consisted predominantly of and . The hypothesis that the secretion volatiles so far identified may be microbiologically produced is examined. 相似文献
955.
956.
Hydrobiologia - The taxonomic composition and biomass of phytoplankton in the San Joaquin River, California, were examined in relation to water depth, flow regime, and water chemistry. Without... 相似文献
957.
F. Fontaine E. Kiefer C. Clément M. Burrus J. L. Druelle 《Trees - Structure and Function》1999,14(2):83-90
In the present work, we described the fate of proventitious epicormic buds on the trunks of 40-year-old Quercus petraea trees and in parallel the vascular trace they produced in the wood. Our results show that small and large individual epicormic
buds can survive as buds for 40 years and that both are composed of a terminal meristem and scales. Meristematic areas are
detected in the scale axils of small buds; in addition to these meristems the large buds also have secondary bud primordia.
The small buds are connected to the pith of the main stem by a unique trace, whereas the large buds are connected by one or
multiple traces. A single trace might imply that the whole bud is still alive and multiple traces might indicate that the
terminal meristem has died. In the latter case, each trace is connected to a secondary bud of the large bud. The buds found
in a cluster are composed of a terminal meristem and scales with axillary meristems in the scale axils. A cluster is connected
to the pith of a stem either by a unique trace when it seems to be the result of partial abscission of an epicormic shoot
or multiple traces when it might have originated from an epicormic bud in which the terminal meristem has died. Whatever the
type of the bud, the vascular trace in the bark is composed of a cambium, secondary xylem and parenchyma cells and the trace
present in the wood had parenchyma cells with vestiges of secondary xylem. Each year, the vascular trace should be produced
in the bark by the cambium of the tree but not by the bud itself. On 40-year-old Q. petraea, we observed a proliferation of epicormic buds and in parallel a multiplication of the number of vascular traces in the trunk,
but the knots caused by the traces of epicormic buds in the wood, either as individuals or in clusters, are minor since their
colours are only slightly darker than those of woody rays and they are less than 2 mm in diameter. The knots will appear when
epicormic buds develop into shoots.
Received: 30 March 1999 / Accepted: 09 June 1999 相似文献
958.
A. V. Timofeev 《Plasma Physics Reports》2003,29(8):683-687
The conditions under which the energy of the electron Langmuir oscillations can escape from the plasma into vacuum are determined in the simplest model of a plane slab of an inhomogeneous cold magnetized plasma in a uniform magnetic field. 相似文献
959.
960.
M J Litzinger D E Brenneman 《Biochemical and biophysical research communications》1984,124(3):979-987
[3H] Nitrendipine binding was partially blocked by the presence of tetrodotoxin in developing spinal cord neurons. In young cultures, 1 micron tetrodotoxin displaced 29% and 26% of [3H] nitrendipine binding from the high and low affinity binding sites, respectively. In one month old cultures, tetrodotoxin had no effect on [3H] nitrendipine binding. The interaction between tetrodotoxin and nitrendipine in young cultures suggests ligand binding site similarities during development. 相似文献