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101.
Intracellular cAMP injection and negative pressure in the patch-electrode increase the interburst closed time of the same potassium ionic channels in the snail neuron membrane. Sodium channels which were registered as change of background noise are activated both by cAMP injection and by negative pressure. These results are considered in connection with data about the unusual biochemistry of the neuron reaction to cAMP. 相似文献
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Alida Liberman 《Bioethics》2017,31(7):495-504
In this article, I address what kinds of claims are of the right kind to ground conscientious refusals. Specifically, I investigate what conceptions of moral responsibility and moral wrongness can be permissibly presumed by conscientious objectors. I argue that we must permit HCPs to come to their own subjective conclusions about what they take to be morally wrong and what they take themselves to be morally responsible for. However, these subjective assessments of wrongness and responsibility must be constrained in several important ways: they cannot involve empirical falsehoods, objectionably discriminatory attitudes, or unreasonable normative beliefs. I argue that the sources of these constraints are the basic epistemic, relational, and normative competencies needed to function as a minimally decent health‐care professional. Finally, I consider practical implications for my framework, and argue that it shows us that the objection raised by the plaintiffs in Zubik v. Burwell is of the wrong sort. 相似文献
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Aflatoxins (AFs) produce singlet oxygen upon their exposure to UV (365-nm) light. Singlet oxygen in turn activates them to mutagens and DNA-binding species. DNA binding and mutagenesis by AFs were enhanced in D2O as compared to reactions in H2O, and a singlet oxygen scavenger inhibited mutagenesis. DNA photobinding of 3H-AFB1 increased in the presence of unlabeled AFB2, and the addition of AFB2 enhanced mutagenesis by AFB1 in a synergistic manner. These results are compatible with the notion that singlet oxygen, formed by one aflatoxin molecule, can readily activate another aflatoxin molecule. This may bear an environmental implication in that the weakly carcinogenic AFB2, which is often produced in nature together with AFB1, may be important in enhancing the activation of AFB1 by sunlight. 相似文献
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Whether interaction between genes is better represented by synergistic or antagonistic epistasis has been a focus of experimental research in bacterial population genetics. Our previous research on evolution of modifiers of epistasis in diploid systems has indicated that the strength of positive or negative epistasis should increase provided linkage disequilibrium is maintained. Here we study a modifier of epistasis in fitness between two loci in a haploid system. Epistasis is modified in the neighborhood of a mutation-selection balance. We show that when linkage in the three-locus system is tight, an increase in the frequency of a modifier allele that induces either more negative or more positive epistasis is possible. Epistasis here can be measured on either an additive or multiplicative scale. 相似文献
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