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31.
The perception of reality by biosystems is based on different, and in certain respects more effective, principles than those utilized by the more formal procedures of science. As a result, what appears as random pattern to the scientific method can be meaningful pattern to a living organism. The existence of this complementary perception of reality makes possible in principle effective use by organisms of the direct interconnections between spatially separated objects shown to exist in the work of J. S. Bell.In memory of J. S. Bell.address for 1990–91 as in footnote 2. 相似文献
32.
2-Phenylsulphonylethyl group has been employed for the first time to protect 3′-terminal phosphodiester to the triester level in the synthesis of dodecathymidylic acid using the phosphotriester approach. 相似文献
33.
Mona S. Minkara Tyler Josephson Connor L. Venteicher Jingyi L. Chen Daniel J. Stein Cor J. Peters 《Molecular physics》2018,116(21-22):3283-3291
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We have synthesized a surface functionalized superparamagnetic iron oxide colloid whose clearance from the vascular compartment was inhibited by asialofetuin but not fetuin. Unlike other particulate or colloidal magnetic resonance (MR) contrast agents, the agent of the current communication is not withdrawn from the vascular compartment by cells of the macrophage-monocyte phagocytic system, as indicated by its selective increase in hepatic relaxation rates. Because of this we refer to this colloid as a hepatic selective (HS) MR contrast agent. At 20 mumol Fe/kg the HS MR agent darkened MR images of liver. The HS MR agent exhibited no acute toxicity when injected into rats at 1800 mumol Fe/kg. Based on these observations, surface functionalized superparamagnetic iron oxide colloids may be the basis of MR contrast agents internalized by receptor mediated endocytosis generally, and by the asialoglycoprotein receptor in particular. 相似文献
36.
Automatic synthesis of oligodeoxynucleotides and mixed oligodeoxynucleotides using the phosphoamidite method 总被引:3,自引:0,他引:3
S Josephson E Lagerholm G Palm 《Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry》1984,38(7):539-545
A simplified procedure for making and using the deoxynucleoside phosphoamidites (1 a-d) in the automated synthesis of oligodeoxynucleotides has been developed. The reagents prepared show good stability in solution. The reactivity of the reagents was found to be directly proportional to their concentrations, which makes it possible to synthesize mixed oligomers in desired ratios. Oligomers up to 45-mer have been synthesized using a coupling cycle of twenty min. 相似文献
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J. Josephson 《Foundations of Physics》1980,10(3-4):243-266
The second-order radial differential equations for the relativistic Dirac hydrogen atom are derived from the Dirac equation treated as a system of partial differential equations. The quantum operators which arise in the development are defined and interpreted as they appear. The splitting in the energy levels is computed by applying the theory of singularities for second-order differential equations to the Klein-Gordon and Dirac relativistic equations. In the Dirac radial equation additional terms appear containing a constant, which is shown to be the radius of the electron. It is concluded that the minute perturbation of the radial eigenfunction in the vicinity of the proton brought about by the extension of the elementary particles, which appears naturally out of the Dirac equations, results in the prediction of the observed splitting of the hydrogen atom energy levels by the Dirac theory. The extension of the particles arises even though the Dirac hydrogen atom is originally formulated for point charges. 相似文献
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Taktak S Weissleder R Josephson L 《Langmuir : the ACS journal of surfaces and colloids》2008,24(14):7596-7598
Magnetic nanoparticles (NPs) have been used to obtain NMR-based sensors for analytes ranging from small molecules to viruses by the conjugation of biomolecules (antibodies, proteins, oligonucleotides) to the surface of NPs. In the presence of an analyte, the NPs form clusters that alter the relaxation time of the surrounding water protons. Here, we show that an organic molecule that binds calcium ions of nonbiological origin, rather than a biomolecule, can be employed to modify the surface of a magnetic NP. When calcium ions are added, they induce NP clustering, providing an NMR-based sensor for these ions. Our work suggests that the many chemistries of nonbiological origin, such as those employed for ion-selective electrodes, can be adapted to obtain NMR-based sensors for ions. 相似文献