abstract：:Octopamine is highly concentrated in neurones of several invertebrate species. Unlike in mammals, octopaminergic neurones in invertebrates are spatially separated from catecholaminergic neurons. In identified nerve cells of Aplysia, however, this amine coexists with other putative neurotransmitters. Octopamine is synt...

journal_title：Nature

authors： Axelrod J,Saavedra JM

更新日期：1977-02-10 00:00:00

abstract：:Eukaryotic structural gene mutations occurring spontaneously in a mouse myeloma cell line offer the opportunity to study somatic mutation in animal cells at the molecular level. Studies on the myeloma protein and on mRNA have enabled us to characterise four such mutants representing four different mutation mechanisms....

journal_title：Nature

authors： Adetugbo K,Milstein C,Secher DS

更新日期：1977-01-27 00:00:00

abstract：:The chemical induction of malignant transformation in BHK cells seems to result from a somatic mutation. Stable transformants, whose frequency is significantly increased by mutagenic carcinogens, can revert to normal and often display temperature-restricted phenotypes indicative of an altered gene product. ...

journal_title：Nature

authors： Bouck N,di Mayorca G

更新日期：1976-12-23 00:00:00

abstract：:A re-analysis of published data on mouse mutation rates induced by X and gamma rays suggests that the kinetics of induction can be analysed by fitting the data to a parabolic curve. We interpret this to mean that a substantial proportion of the induced mutations results from gross chromosomal changes such as deletions...

journal_title：Nature

authors： Abrahamson S,Wolff S

更新日期：1976-12-23 00:00:00

abstract：:Transposable elements of DNA that are structurally defined and genetically discrete units seem to have an important role in the evolution of bacterial plasmids. Recombination occurring at the termini of such elements can result in the joining together of unrelated DNA segments that lack extensive nucleotide sequence h...

journal_title：Nature

authors： Cohen SN

更新日期：1976-10-28 00:00:00

abstract：:Microsomes prepared from rabbit or pig aortas transformed endoperoxides (PGG2 or PGH2) to an unstable substance (PGX) that inhibited human platelet aggregation. PGX was 30 times more potent in this respect than prostaglandin E1. PGX contracted some gastrointestinal smooth muscle and relaxed certain isolated blood vess...

journal_title：Nature

authors： Moncada S,Gryglewski R,Bunting S,Vane JR

更新日期：1976-10-21 00:00:00

abstract：:In Drosophila melanogaster, the rRNA genes (rDNA) are clustered at single sites on two non-homologous chromosomes, the X and Y. Examination of the structure of X and Y rDNAs with restriction endonucleases reveals that the X rDNA contains repeating units not present in the Y. Such observations, as well as genetic evide...

journal_title：Nature

authors： Tartof KD,Dawid IG

更新日期：1976-09-02 00:00:00

abstract：:oop RNA, which is initiated at the po promoter and is 81 nucleotides long, can function as a leader sequence for the lambda immunity establishment transcription, previously believed to originate at a special promoter pre located in the y region. Thus, oop RNA seems to have a dual role, either favouring the lytic cycle...

journal_title：Nature

authors： Honigman A,Hu SL,Chase R,Szybalski W

更新日期：1976-07-08 00:00:00

abstract：:A short exposure of primary cultures of mouse mammary tumour cells to glucocorticoids results in at least a three-fold stimulation of mammary tumour virus (MTV) production. Specific interaction of glucocorticoids with the cytoplasmic and nuclear receptors can also be demonstrated. The biological potency of various ste...

journal_title：Nature

authors： Shyamala G,Dickson C

更新日期：1976-07-08 00:00:00

abstract：:First-order difference equations arise in many contexts in the biological, economic and social sciences. Such equations, even though simple and deterministic, can exhibit a surprising array of dynamical behaviour, from stable points, to a bifurcating hiearchy of stable cycles, to apparently random fluctuations. There ...

journal_title：Nature

authors： May RM

更新日期：1976-06-10 00:00:00

abstract：:Elongation factor Tu is present in a fourfold excess over the amount seemingly involved in protein synthesis. It is identical to a major protein which we have found associated with the plasma membrane. The possibility of a specific role in that location is considered. ...

journal_title：Nature

authors： Jacobson GR,Rosenbusch JP

更新日期：1976-05-06 00:00:00

abstract：:TMV RNA is not an efficient template for translation of the viral coat protein, in spite of containing nucleotide sequences coding for the protein. Efficient translation requires the prior synthesis within infected cells of a smaller RNA carrying only a portion of the information encoded in the whole genome. ...

journal_title：Nature

authors： Hunter TR,Hunt T,Knowland J,Zimmern D

更新日期：1976-04-29 00:00:00

abstract：:Noradrenaline releases prostaglandins in the kidney, and in rats these augment rather than reduce vasoconstriction produced by the amine. Homogenates of kidneys of New Zealand rats inbred for hypertension exhibit lower prostaglandin inactivation by 15-hydroxydehydrogenase than controls. At the same time, augmentation ...

journal_title：Nature

authors： Armstrong JM,Blackwell GJ,Flower RJ,McGiff JC,Mullane KM,Vane JR

更新日期：1976-04-15 00:00:00

abstract：:Five new double-mutant haemoglobins composed of betaS chains and alpha chains with different substitutions, which are located at the surface of the tetramer, have been prepared. Although all the hybrids are more soluble than deoxyhaemoglobin S, the individual differences between these molecules make it possible to eva...

journal_title：Nature

authors： Benesch RE,Yung S,Benesch R,Mack J,Schneider RG

更新日期：1976-03-18 00:00:00

abstract：:A model catalyst is described which has properties in common with carbonic anhydrase. The model demonstrates the availability of a mechanism, previously only hypothetical, for the action of the enzyme. It also shows, however, that this mechanism alone is not adequate to produce the high activity of the enzyme. ...

journal_title：Nature

authors： Woolley P

更新日期：1975-12-25 00:00:00

abstract：:The extreme resistance of bacterial endospores to heat may result from dehydration of the central protoplast brought about and maintained by osmotic activity of expanded electronegative peptidoglycan polymer, and positively charged counterions associated with it, in the surrounding cortex. The cortex may thus act as a...

journal_title：Nature

authors： Gould GW,Dring GJ

更新日期：1975-12-04 00:00:00

abstract：:Tectal polarity for retinal connections remains reversible long after the anatomical pattern of neural structures has been determined. Cells in the diencephalon seem to control this polarity. Following certain embryonic operations, the diencephalon developed behind the tectum. In such cases, the polarity of the retino...

journal_title：Nature

authors： Chung SH,Cooke J

更新日期：1975-11-13 00:00:00

abstract：:A 7-A resolution map of the purple membrane has been obtained by electron microscopy of tilted, unstained specimens. The protein in the membrane contains seven, closely packed, alpha-helical segments which extend roughly perpendicular to the plane of the membrane for most of its width. Lipid bilayer regions fill the s...

journal_title：Nature

authors： Henderson R,Unwin PN

更新日期：1975-09-04 00:00:00

abstract：:The process of DNA recognition by the activated form of the restriction endonuclease from E. coli K involves three enzyme-DNA complexes which can be differentiated experimentally. These are: an initial complex formed at a nonspecific site; a recognition complex involving the host specificity site; and a cleavage compl...

journal_title：Nature

authors： Yuan R,Bickle TA,Ebbers W,Brack C

更新日期：1975-08-14 00:00:00

abstract：:Corticosteroids as well as non-steroid anti-inflammatory drugs inhibit the prostaglandin-mediated vasodilatation accompanying lipolysis in subcutaneous fat. Whereas the non-steroids produce their effect by inhibition of prostaglandin synthesis, however, corticosteroids inhibit their release. This mechanism may be the ...

journal_title：Nature

authors： Lewis GP,Piper PJ

更新日期：1975-03-27 00:00:00

abstract：:An analysis of 15 protein structures indicates: First, the loss of accessible surface area by monomeric proteins on folding-proportional to hydrophobic energy-is a simple function of molecular weight; second, the proportion of polar groups forming intramolecular hydrogen bonds is constant; and third, protein interiors...

journal_title：Nature

authors： Chothia C

更新日期：1975-03-27 00:00:00

abstract：:The nucleotide sequence of the RNA polymerase binding site at a promotor on fd RF DNA has been determined in comparison with the starting sequence of RNA initiated at this promoter. The RNA polymerase binding site contained the startpoint of transcription in the centre and a region with twofold symmetry in the non-tra...

journal_title：Nature

authors： Sugimoto K,Okamoto T,Sugisaki H,Takanami M

更新日期：1975-02-06 00:00:00

abstract：:Lord Rothschild presents his personal views about the terminology used to describe research and development. ...

journal_title：Nature

authors： Rothschild L

更新日期：1972-10-13 00:00:00

abstract：:Published data from X-ray telescopes are not adequate to reveal the fluctuations in the surface brightness of the background radiation caused by clustering or superclustering of the sources giving rise to the background. ...

journal_title：Nature

authors： Webster AS

更新日期：1972-07-07 00:00:00

abstract：:Oxygen isotope analyses of Spondylus shells from neolithic sites suggest that the source for the shells used as ornaments in the Balkans and central Europe during the fourth millennium BC was the Aegean and not the Black Sea. The trade in Spondylus may have taken the form of an exchange of gifts. ...

journal_title：Nature

authors： Shackleton N,Renfrew C

更新日期：1970-12-12 00:00:00

abstract：:Helium-neon lasers emitting at 632.8 nm can influence the phytochrome controlled growth and development of plants more than a quarter of a mile away. It may therefore be possible to control the growth of crops using lasers to activate the phytochrome system. ...

journal_title：Nature

authors： Paleg LG,Aspinall D

更新日期：1970-12-05 00:00:00

abstract：:An attempt is made to understand the characteristics of pulsar slowdown in terms of various possible emission mechanisms. Though magnetic-dipole radiation seems to be dominant, the deviations from a pure dipolar decay are large compared with errors in measurement and indicate the presence of more complicated braking m...

journal_title：Nature

authors： Papaliolios C,Carleton NP,Horowitz P

更新日期：1970-10-31 00:00:00

abstract：:Is the big-bang hot, warm or cold? And are galactic masses determined by the interplay of gravitational and strong interactions in the very early universe? ...

journal_title：Nature

authors： Harrison ER

更新日期：1970-10-17 00:00:00

abstract：:The neutron superfluid in most neutron stars should be in a highly turbulent state. If so, this turbulence drastically alters its rotational properties. ...

journal_title：Nature

authors： Greenstein G

更新日期：1970-08-22 00:00:00

abstract：:Data from a rocket experiment show details which were not known from ground-based observations. ...

journal_title：Nature

authors： Sudbury GC,Ingham MF

更新日期：1970-05-09 00:00:00

abstract：:A rapid decrease in shear velocity in the suboceanic mantle is used to infer the thickness of the lithosphere. It is proposed that new and highly precise group velocity data constrain the solutions and imply a thickness near 70 km. ...

journal_title：Nature

authors： Kanamori H,Press F

更新日期：1970-04-25 00:00:00

abstract：:Flash spectra of the total solar eclipse throughout all its phases have been obtained in the extreme ultraviolet for the first time. ...

journal_title：Nature

authors： Speer RJ,Garton WR,Morgan JF,Nicholls RW,Goldberg L,Parkinson WH,Reeves EM,Jones TJ,Paxton HJ,Shenton DB,Wilson R

更新日期：1970-04-18 00:00:00

abstract：:The subsidence history of the Bahamian Platform points to a non-uniform rate of sea-floor spreading since the beginning of the Cretaceous. Lower Cretaceous rates of perhaps 5 cm/yr led to an active trench system at the boundary between the American and Caribbean lithosphere plates, and the rapid subsidence of the cont...

journal_title：Nature

authors： Lynts GW

更新日期：1970-03-28 00:00:00

abstract：:A first step towards somatic hybridization in plants has been achieved. Protoplasts have been isolated and seen to fuse. ...

journal_title：Nature

authors： Power JB,Cummins SE,Cocking EC

更新日期：1970-03-14 00:00:00