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361.
Prof. Dr. J. Oldenburg S. Rost H. Seidel M. Watzka C.R. Müller-Reible 《Medizinische Genetik》2008,20(2):230-235
The recent identification of VKORC1 has made important contributions to our understanding of the vitamin K cycle. The VKORC1 enzyme was shown to be the molecular target of coumarin drugs. Mutations and polymorphisms in coding and noncoding regions of the VKORC1 gene have been shown to cause both a partial to total coumarin resistance and coumarin sensitivity. Availability of molecular diagnostics (VKORC1, CYP2C9) and drug monitoring by HCPLC (determination of coumarin, vitamin K, and vitamin K epoxide levels) is helpful for detecting hereditary and acquired factors influencing coumarin therapy. In the future, these tools may be instrumental in designing individualized oral anticoagulation therapy regimens. 相似文献
362.
363.
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
364.
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
365.
366.
367.
368.
It has been proposed that amplification of genes for esterase that provide resistance to insecticides may originate from
transposition events. To test this hypothesis, we have constructed a minigene coding for a soluble acetylcholinesterase under
the control of a nontissue-specific promoter (hsp70). When introduced into Drosophila, the gene is expressed in all tissues and the extra acetylcholinesterase produced confers a low level of insecticide resistance
(twofold). The minigene was mobilized by crossing the initial transformant with a strain providing a source of P-element transposase.
After 34 generations of exposure to the organophosphate parathion, we obtained a strain with a higher resistance (fivefold).
This strain had only one extra Ace gene, which overexpressed acetylcholinesterase. Thus, following transposition, resistance resulted from the overexpression
of a single copy of the gene and not from gene amplification.
Received: 9 August 1996 / Accepted: 27 May 1997 相似文献
369.
Field observations of two sympatric pitheciine species reveal that the positional repertoire of the white-faced saki, Pithecia pithecia, is dominated by leaping behaviors, whereas the bearded saki, Chiropotes satanas, is predominantly quadrupedal. Examination and comparison of the postcranial skeletal morphologies and limb proportions of these species display numerous features associated with their respective locomotor behaviors. These observations accord with associations found in other primate and mammalian groups and with predictions based on theoretical and experimental biomechanics. Preliminary observations of the skeletal morphology of Cacajao calvus demonstrate a marked similarity to that of Chiropotes. The fossil platyrrhine Cebupithecia sarmientoi displays greater similarity to Pithecia, suggesting that its positional repertoire also included significant leaping and clinging behaviors. 相似文献
370.
D. Tab Rasmussen 《International journal of primatology》1985,6(5):501-517
Breeding records of 11 taxa of captive lemurs housed at the Duke University Primate Center (DUPC), North Carolina, were analyzed
for differences in the timing of births, for the relationship between breeding season and photoperiod, and for differences
in litter size. At DUPC there are significant differences in the timing of births among certain taxa, including differences
among some subspecies of Lemur fulvus.However, changes in latitude result in changes in the timing of the breeding season. Lemurs moved to higher latitudes mate
at lower light-dark ratios than on Madagascar. The data presented here are consistent with the following model: a photoperiodic
cue initiating reproductive activity, presumably a light-dark threshold, precedes the actual mating season by approximately
2 months, with an intervening period of physiological and social preparation. On Madagascar, selection may have favored births
that coincide with the end of dry seasons and the beginning of wet seasons, which results in lactation and weaning during
times of resource abundance. Taxa from the north and east have the highest mean litter sizes; those from the west have the
lowest. 相似文献