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181.
Rosette and single-element strain gauges were implanted on the tibia in 2 dogs and recordings were made during locomotion on a treadmill. At foot contact and during the swing phase of locomotion, bone strains were low and directions of the principal strains were variable. There was a large shift in the directions of the principal strains at the beginning of the stance phase and bone strains were considerably higher. Peak strain occurred midway through the stance phase. At that time, the maximum principal strain (tension) was directed upwards and anteriorly between 30 and 60 degrees with respect to the long axis of the tibia. These bone strain patterns in the dog are similar to those found in sheep while both differ markedly from those found in humans. 相似文献
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185.
To control the environmentally detrimental impact of acid rock drainage, two different countermeasures, layers of acid-buffering
materials and sodium dodecyl sulphate addition, were tested for their efficiency in laboratory percolation experiments. In
the experiment with a layer of calcium bentonite, only the iron output was reduced. The experiments with layers of concrete
grains demonstrated a decrease of the microbial activity as well as a precipitation of heavy-metal ions, whereas the cell
numbers did not decrease. Furthermore, finely grained concrete (1–5 mm) formed a water-tight hardpan (self-sealing layer).
In the experiment with 1 mM sodium dodecyl sulphate, all the microorganisms were killed and hence metal sulphide dissolution
was stopped. With 0.1 mM sodium dodecyl sulphate only a short, transient inhibition of leaching was achieved. The bacteria
remained alive.
Received: 16 February 1998 / Accepted: 23 February 1998 相似文献
186.
T. P. Malyshkina 《Paleontological Journal》2012,46(4):392-399
Two new species of carcharhinid sharks from the Late Eocene deposits (Tavda Formation) of the southern Trans-Urals, Abdounia vassilyevae sp. nov., previously determined as A. aff. beaugei, and A. lata sp. nov., are described. To date, up to five Priabonian species of Abdounia have been recorded. New finds supplement the data on diversity, evolution, and paleobiogeography of Abdounia. 相似文献
187.
Monoclonal antibodies were used to investigate the immunochemistry of human erythrocyte acetylcholinesterase (acetylcholine acetylhydrolase, EC 3.1.1.7). A series of experiments on the sedimentation velocity and Stokes radius of acetylcholinesterase and its immune complexes indicated that each antibody recognized a single high-affinity binding site (epitope) on the monomeric enzyme. Further analysis suggested that the antibody-binding sites were replicated on multimeric enzyme forms but were subject to steric hindrance between nearby IgG molecules or adjacent enzyme subunits. The cellular localization of the epitopes was studied by measuring the binding of monoclonal antibodies to the cholinesterase of intact erythrocytes. The results implied that most of the epitopes are exposed to the external media. However, one antibody failed to bind to intact cells, despite a relatively high affinity for detergent-solubilized antigen, possibly because its epitope is buried in the lipid bilayer. 相似文献
188.
Ting Zhang Bai‐Ge Miao Bo Wang Yan‐Qiong Peng Clive T. Darwell 《Ecological Entomology》2019,44(6):844-848
1. Species interactions in tightly bound ecological mutualisms often feature highly specialised species' roles in which competitive exclusion may preclude multi‐species coexistence. Among the 800 fig (Ficus) species, it was originally considered that each was pollinated by their own wasp (Agaonidae). However, recent investigations show that this ‘one‐to‐one’ rule often breaks down, as fig species regularly host multiple agaonids but in ways suggesting that competitive processes still mediate biodiversity outcomes. 2. A phenological survey was conducted of the fig–fig wasp pair, Ficus microcarpa and its associated pollinating wasp, alongside its sister species, the cheating wasp, in Xishuangbanna, China. 3. Reproductive output underwent extreme seasonal variation. Seed and pollinator production fell markedly during cooler, drier months, although high levels of fig production continued. However, this resource was predominantly utilised by the cheater species, which offers no pollination services. Pollinators and cheaters rarely co‐occur, suggesting that temporal coexistence is constrained by competition for access to figs. 4. The overall findings indicate periodic rearrangements of mutualism dynamics, probably resulting from a strongly seasonal environment. Sympatric co‐occurrence may result from a window of opportunity for a functionally divergent agaonid, potentially due to constraints on the main pollinator in adapting to variable year‐round conditions that prevent competitive exclusion. 相似文献
189.
Summary A murine hybridoma (455) was cultured in four different serum free media formulations, and a newborn calf serum supplemented medium was used as a basis of comparison. The serum supplemented medium supports a higher cell growth rate and results in a higher IgG titer. However, the antibody secretion rate on a per cell basis is higher in the serum free media, indicating that serum could be inhibitory to antibody secretion. The results identify the possibility of a least eliminating serum during the monoclonal antibody production phase. 相似文献
190.
N. P. Todaria 《Biologia Plantarum》1986,28(4):280-287
A comparative study of dark respiration and effects of high and low temperature on dark respiration in five greenhouse cultivated tropical and sub-tropical species was made. The respiration rates determined manometrically were low in all species. Respiration rates increased with increasing temperature. Low temperature treatment accelerated the rate of respiration at 25 °G except in two species. An attempt has been made to determine the critical and optimum temperature for these species. The respiratory behaviour of these species has been discussed with respect to their original habitats and prevailing environmental conditions. 相似文献