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1.
Purdy LM 《Bioethics》1989,3(1):18-34
The morality of surrogate mothering is analyzed from a "consequentialist" framework which attempts to separate those consequences that invariably accompany a given act from those that accompany it only in particular circumstances. Critics of surrogacy argue that it transfers the burden and risk of pregnancy onto another woman, separates sex and reproduction, and separates reproduction and childrearing; none of these acts is necessarily wrong, either morally or for women's or society's basic interests. While surrogate mothering can be rendered immoral if women are coerced into the practice or become victims of subordinating or penalizing contracts, it has the potential to empower women and increase their status in society by providing a job that is less risky and more enjoyable than other jobs women are forced to take and by achieving greater social recognition for reproductive labor. 相似文献
2.
Purdy LM 《Bioethics》1990,4(4):273-291
Purdy explores the argument that women's rights to control their bodies should be subordinated to the welfare of their fetuses. She gives examples ofinstances where women's decisions about pregnancy and childbirth have been overridden by physicians and judges. She examines the nature of the mother fetus relationship, the social context of the current conflict between maternal and fetal rights, and the extent of a woman's legally enforceable duty to her fetus. Purdy acknowledges that women may owe a reasonable duty to their fetuses to try to prevent disease or handicap. However, given the uncertainties of modern medicine, the value-laden nature of many physicians' decisions, and the lack of adequate adequate prenatal care, women should not be held responsible for situations that are due largely to society's shortcomings. Purdy concludes that it is unjust to use the law to coerce women into accepting medical advice. 相似文献
3.
4.
Rapid Extraction of DNA and rRNA from Sediments by a Novel Hydroxyapatite Spin-Column Method 总被引:5,自引:3,他引:2 下载免费PDF全文
We describe a novel hydroxyapatite spin-column method of nucleic acid extraction from natural sediments by which DNA and rRNA can be extracted separately. This very rapid method produces pure nucleic acid that can be utilized in some of the most common molecular biological procedures used in the analysis of natural microbial communities. 相似文献
5.
Tanya Tadey William C. Purdy 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1995,671(1-2)
Various modes of chromatography are available for lipoprotein separation. Gel permeation and affinity chromatography are used for preparative purposes and to separate lipoproteins according to size and apolipoprotein content, respectively. Development of rigid supports for gel permeation has led to large improvements in speed and resolution. Reversed-phase high-performance liquid chromatography (HPLC) of apolipoproteins offers the best performance in terms of speed and resolution of structural variants. Due to its high speed and superior resolving power, the recently developed technique of capillary electrophoresis should emerge as an important method for lipoprotein analysis. 相似文献
6.
Genetic variation was examined by electrophoresis in 14 populations of Stellaria arenicola, an endemic of the Athabasca sand dunes in northern Saskatchewan, Canada, and seven populations of S. longipes, its progenitor. Three of the 5. longipes populations were sympatric with the endemic. Populations of the endemic were found to have fewer alleles per polymorphic locus (2.21 vs. 2.37), fewer polymorphic loci (29.9 vs. 33.8), and lower genetic diversity (0.087 vs. 0.107) than populations of the progenitor. Genetic identities for all pairs of populations were high (0.932 to 1.000). The endemic had one novel allele and shared ten alleles with progenitor populations from the sand dunes that were not found in other populations of S. longipes. Populations of both species were found to partition most of their genetic variation within populations. An investigation of the multilocus outcrossing rates revealed that S. arenicola had higher rates of selling and biparental inbreeding than S. longipes. This study suggests that partial genetic isolation through a shift in the breeding system, in addition to previously reported strong directional selection, has been important in the sympatric evolution of the endemic S. arenicola. The close genetic relationship between populations of S. arenicola and S. longipes found on the Athabasca sand dunes supports the suggestion that the endemic evolved while sympatric to the gene pool of the progenitor species that is found presently in the region. 相似文献
7.
Ian P. Thompson Mark J. Bailey Richard J. Ellis Kevin J. Purdy 《FEMS microbiology letters》1993,102(2):75-84
Abstract The cellular fatty acid composition of six bacterial species isolated from the seeds and leaves of sugar beet ( Beta vulgaris ) and from soil were analysed. The quantitative data from the fatty acid methyl ester (FAME) profiles were highly reproducible. Numerical analysis of Xanthomonas maltophilia . FAME profiles sub-grouped strains according to when they were isolated in the growing season. The analytical method used was sensitive enough to differentiate strains of Klebsiella terrigena isolated from either soil or leaves. The results from this study confirm reports that analyses of bacterial FAME composition were rapid to perform, specific and allowed differentiation of strains within the same species. 相似文献
8.
Inhibition of dihydropteridine reductase by dopamine 总被引:1,自引:1,他引:0
Dihydropteridine reductase has been purified 900-fold from rat liver. Dopamine inhibited the enzyme up to 50% at a concentration of 0.11mm. In the presence of dopamine the enzyme gave non-hyperbolic v-against-[S] plots. This enzyme may have a role in control of dopamine biosynthesis. 相似文献
9.
Evidence for nonclassical alpha adrenoceptor blockade by prazosin in isolated rabbit blood vessels 总被引:6,自引:0,他引:6
In isolated rabbit ear artery, prazosin shifted the concentration-response curve for norepinephrine (NE) to the right and increased the slope of the curve in the ED50 region. Prazosin caused a smaller shift to the right of the concentration-response curve for NE in rabbit small saphenous vein and had no effect on the slope in the ED50 region. The prazosin-induced increase in the slope of the NE concentration-response curve did not occur in the ear artery when neuronal and extraneuronal uptake were inhibited by desipramine (DMI) and deoxycorticosterone acetate (DOCA). Prazosin concentration ratios were significantly larger in the ear artery than in the small saphenous vein at all prazosin concentrations in the presence or absence of DMI and DOCA. Significant differences were found between prazosin dissociation constants (KB) determined at three concentrations of prazosin in ear artery. No such differences were found between phentolamine dissociation constants determined in this vessel. Prazosin dissociation constants determined in small saphenous vein were higher than those determined in ear artery. These findings suggest that prazosin behaves as a noncompetitive antagonist in ear artery and that there are differences between the alpha adrenoceptors of the ear artery and those of the small saphenous vein. 相似文献
10.
The axoplasmic migration of ribosomes has been detected in the visual system of the chick. Monocular injection of radioactive uridine or an amino acid mixture was followed by sedimentation analysis in sucrose or cesium sulfate density gradients, of ribosomes prepared from the retinae of injected eyes and the left and right optic lobes. By this means both RNA and protein components of ribosomes were found to migrate from the retina to the innervated contralateral optic lobe. Following denervation of the distal nerve segment by eye removal, the stability of the transported RNA was reduced, suggesting its presynaptic location. The transport of RNA was not significantly imparied by intraocular injection of inhibitors of informational RNA or mitochondrial RNA synthesis prior to injection of radioactive uridine but was depressed by a low dose of actinomycin D. 相似文献