abstract：:Red colobus are one of a small number of primate species in which females have been reported to transfer between breeding groups more commonly than males. Several authors have hypothesised that in such species transference may serve to reduce the risk to females of producing offspring of lower fitness through inbreedi...

journal_title：Nature

authors： Marsh CW

更新日期：1979-10-18 00:00:00

abstract：:Lecithin is a major structural component of biological membranes. Because of their amphipathic nature, lecithin and related phospholipids tend to aggregate as bilayer structures in which the hydrophilic head groups are orientated towards the surface and the hydrophobic hydrocarbon chains towards the interior. A detail...

journal_title：Nature

authors： Pearson RH,Pascher I

更新日期：1979-10-11 00:00:00

abstract：:The mechanism by which insulin regulates cellular metabolism remains unknown although indirect evidence suggests that alterations in intracellular calcium are important. More specifically, it has been proposed that insulin triggers an increase in intracellular calcium which is responsible for the subsequent modificati...

journal_title：Nature

authors： Pershadsingh HA,McDonald JM

更新日期：1979-10-11 00:00:00

abstract：:The difficulty of working with the intact brain in vivo has led to the increasing use of nerve cell cultures in neurobiology. However, dissociated cells cannot be unambiguously identified by morphological criteria before the third week in culture, for it is not until then that the basic morphology and size of neurones...

journal_title：Nature

authors： Hooghe-Peters EL,Fowlkes BJ,Hooghe RJ

更新日期：1979-10-04 00:00:00

abstract：:Medawar has suggested that the major histocompatibility gene complex (MHC) might be involved in the contact inhibition of movement shown by fibroblasts and epithelia. Contact inhibition of movement is that reaction of cells which stops the movement of one cell over another and thus leads to monolayering and other feat...

journal_title：Nature

authors： Curtis AS,Rooney P

更新日期：1979-09-20 00:00:00

abstract：:It has been proposed that the trans-sarcolemmal influx of Ca2+ occurring during the plateau of the mammalian cardiac action potentials is insufficient in itself to activate the myofilaments, but can trigger a release of Ca2+ from the sarcoplasmic reticulum (SR) which is sufficient for activation. The demonstration of ...

journal_title：Nature

authors： Fabiato A,Fabiato F

更新日期：1979-09-13 00:00:00

abstract：:The requirement of metabolic energy for the interaction of polyene macrolide antibiotics with eukaryotic organisms remains a controversial subject (for review see ref. 1) It has been claimed that the lethal binding of these antibiotics to the sterol target component of the hydrophobic core of the membrane, in accordan...

journal_title：Nature

authors： Malewicz B,Borowski E

更新日期：1979-09-06 00:00:00

abstract：:The neuronal structure and connectivity underlying receptive field organisation of cells in the cat visual cortex have been investigated. Intracellular recordings were made using a micropipette filled with a histochemical marker, which was injected into the cells after their receptive fields had been characterised. Th...

journal_title：Nature

authors： Gilbert CD,Wiesel TN

更新日期：1979-07-12 00:00:00

abstract：:A three-dimensional image of tubulin protofilaments, reconstructed to 20 A resolution from electron micrographs of negatively stained zinc-induced sheets, has been used to generate an improved model for microtubule substructure. This model has been used to phase a reconstructed image from X-ray amplitudes, which is co...

journal_title：Nature

authors： Amos LA,Baker TS

更新日期：1979-06-14 00:00:00

abstract：:The gal operon of Escherichia coli is controlled by two independent promotors--one is activated and the other inhibited by cyclic AMP and cyclic AMP receptor protein. The two promotors are modulated, however, by the same operator locus and receptor protein. ...

journal_title：Nature

authors： Adhya S,Miller W

更新日期：1979-06-07 00:00:00

abstract：:TPA (12-O-tetradecanoyl-phorbol-13-acetate) reversibly inhibits the binding of (125)I-labelled epidermal growth factor (EGF) to treated mouse and human cells, but does not affect the binding of various other ligands to their membrane receptors. It alters the affinity of the receptors for EGF without changing the total...

journal_title：Nature

authors： Shoyab M,De Larco JE,Todaro GJ

更新日期：1979-05-31 00:00:00

abstract：:MANY ferromanganese minerals have been found in marine manganese deposits. There have been terminological and intrinsic problems in accurately defining the constituents of manganese nodules(1), but 10-A manganite and delta-MnO(2) which are often compared with todorokite and birnessite seem to be the only major constit...

journal_title：Nature

authors： Usui A

更新日期：1979-05-31 00:00:00

abstract：:SEVERAL dioecious marine brown algae have been valuable in studying chemical communication during sexual reproduction. For example, female gametes of Ectocarpus siliculosus, Cutleria multifida and Fucus serratus secrete olefinic hydrocarbons into the seawater to attract male gametes(1-3). A more complex system is foun...

journal_title：Nature

authors： Müller DG,Gassmann G,Lüning K

更新日期：1979-05-31 00:00:00

abstract：:AFTER exposure to secretagogues the small intestine changes from a tissue that absorbs fluid and electrolyte from lumen to blood into a tissue that secretes electrolyte and fluid into the lumen(1-4). It has been shown that this secretion results from an increase in the passive Cl(-) permeability of the mucosal border,...

journal_title：Nature

authors： Ilundain A,Naftalin RJ

更新日期：1979-05-31 00:00:00

abstract：:In Dictyostelium discoideum, carbohydrate binding proteins (CBPs) or lectins have been implicated in the molecular basis of cellular cohesion. To determine the role of these CBPs, we have attempted to isolate structural gene mutants in which the CBPs have a defective affinity for carbohydrate ligands. We now report th...

journal_title：Nature

authors： Ray J,Shinnick T,Lerner R

更新日期：1979-05-17 00:00:00

abstract：:A hybrid gene was constructed between the beta-lactamase gene of plasmid pBR322 and the cloned coding sequence for rat growth hormone. This gene is expressed in bacteria and growth hormone sequences are detectable by immunological methods. ...

journal_title：Nature

authors： Seeburg PH,Shine J,Martial JA,Ivarie RD,Morris JA,Ullrich A,Baxter JD,Goodman HM

更新日期：1978-12-21 00:00:00

abstract：:The bithorax gene complex in Drosophila contains a minimum of eight genes that seem to code for substances controlling levels of thoracic and abdominal development. The state of repression of at least four of these genes is controlled by cis-regulatory elements and a separate locus (Polycomb) seems to code for a repre...

journal_title：Nature

authors： Lewis EB

更新日期：1978-12-07 00:00:00

abstract：:A set of restriction fragments cloned into phage lambda vectors has allowed us to locate a site necessary for full rpoBC expression. We find that these genes for the two large subunits of RNA polymerase and the genes, rplL and rplJ, for two ribosomal proteins, form a single operon. ...

journal_title：Nature

authors： Linn T,Scaife J

更新日期：1978-11-02 00:00:00

abstract：:A temperature sensitive mutant has been isolated for the first time from a replication defective acute leukaemia virus, AEV. In vivo, at 41 degrees C, the mutant shows a reduced leukaemogenic potential. In vitro, in erythroblasts transformed at 35 degrees C, haemoglobin synthesis can be induced by a shift to 41 degree...

journal_title：Nature

authors： Graf T,Ade N,Beug H

更新日期：1978-10-12 00:00:00

abstract：:The kinetics of the thrombin-catalysed release of fibrino-peptides A and B from human fibrinogen have been investigated and a mechanism correlating the release of fibrinopeptides to fibrin formation is presented. The sequential release of fibrinopeptides results in sequential activation of two sets of polymerisation s...

journal_title：Nature

authors： Blombäck B,Hessel B,Hogg D,Therkildsen L

更新日期：1978-10-12 00:00:00

abstract：:A steady electric field of 30 mV across a single embryonic muscle cell produces accumulation of acetylcholine receptors toward one pole of the cell within 1 h. The movement is electrophoretic in nature and the accumulation results in the formation of stable, metabolically independent receptor aggregates. ...

journal_title：Nature

authors： Orida N,Poo MM

更新日期：1978-09-07 00:00:00

abstract：:The promoter for a weakly expressed constitutive gene, the lactose repressor gene (lacI), has been sequenced, along with an 'up' promoter mutation Iq. The 10-fold enhancement in I expression found in Iq is the result of a single base change at position -35. To facilitate the sequencing, the lacI gene was cloned in a s...

journal_title：Nature

authors： Calos MP

更新日期：1978-08-24 00:00:00

abstract：:Intestinal parasites are common in man and animals and can cause severe disease. Knowledge of immunity to such infections is limited and comes largely from studies using laboratory host-parasite systems. Understanding how immunity can operate, and why it often does not, is not only of intrinsic interest but necessary ...

journal_title：Nature

authors： Wakelin D

更新日期：1978-06-22 00:00:00

abstract：:The taxonomy of a parasite can be an important guide to its pathogenic characteristics. A wide range of anatomical, biochemical and behavioural tests is now being developed to define different strains and subspecies of the main tropical parasites. ...

journal_title：Nature

authors： Godfrey DG

更新日期：1978-06-22 00:00:00

abstract：:Insulin binding to its receptor leads to negatively cooperative interactions among the receptor sites. Studies with 29 insulin analogues (animal insulins and proinsulin, insulin-like growth factor and chemically modified insulins) which vary 1,000-fold in their affinity for the receptor and in their biological potency...

journal_title：Nature

authors： De Meyts P,Van Obberghen E,Roth J

更新日期：1978-06-15 00:00:00

abstract：:Microcrystals of the lipoprotein-phosphoprotein complex which are found in the oocytes of Xenopus laevis were examined using electron microscopy. Analysis of Fourier transforms of the images of the (010) and (001) projections showed the space group to be P2(1)22(1). Ten projections were combined to produce a map of th...

journal_title：Nature

authors： Ohlendorf DH,Wrenn RF,Banaszak LJ

更新日期：1978-03-02 00:00:00

abstract：:During the fission yeast cell cycle, the rate of polyadenylated messenger RNA synthesis doubles when the cell reaches a critical size. This size-related control maintains average mRNA content in balance with total cell mass during exponential growth, even in cells growing at different absolute growth rates per cell. ...

journal_title：Nature

authors： Fraser RS,Nurse P

更新日期：1978-02-23 00:00:00

abstract：:The multi-disciplinary role of intermediate energy proton accelerators in pure and applied nuclear physics is discussed with particular reference to the experimental programmes at LAMPF (Los Alamos Meson Physics Facility) and SIN (Swiss Institute for Nuclear Research, Zurich). ...

journal_title：Nature

authors： Davies JD,Batty CJ,Green K

更新日期：1977-12-22 00:00:00

abstract：:Control of protein synthesis is associated with changes in the ratio of intracellular Na+ to K+ in the cultured embryonic chick lens. Correlations of intracellular Na+/K+ ratios with crystallin synthesis and cataract formation in vitro suggest that the Na+/K+ ratio may have an important role in the regulation of prote...

journal_title：Nature

authors： Shinohara T,Piatigorsky J

更新日期：1977-12-01 00:00:00

abstract：:An evolutionary view of ageing suggests that mortality may be due to an energy-saving strategy of reduced error regulation in somatic cells. This supports Orgel's 'error catastrophe' hypothesis and offers a new basis for the study of normal and abnormal ageing syndromes and of apparently immortal transformed cell line...

journal_title：Nature

authors： Kirkwood TB

更新日期：1977-11-24 00:00:00

abstract：:Keratinocytes of three different epithelia grown in cell culture express a large number of differentiation markers with either no differences or relatively small differences, depending on the species. Much of the distinctive phenotype of these epithelia in vivo must be due to external modulation and relatively little,...

journal_title：Nature

authors： Sun TT,Green H

更新日期：1977-10-06 00:00:00

abstract：:alpha-Neurotoxins bind to cholinergic receptor, block transmission, and induce sprouting of retinal terminals in the toad tectum. New connections retain an orderliness that suggests a selective affinity between presynaptic terminals. The results suggest that postsynaptic cells exert a control, associated with receptor...

journal_title：Nature

authors： Freeman JA

更新日期：1977-09-15 00:00:00

abstract：:Collections in early Middle Miocene deposits at Pasalar in Turkey have yielded a very rich fauna. Included in this are two hominoid species referred here to Sivapithecus darwini (Abel) 1902 and Ramapithecus wickeri (Leakey) 1962. These are both more primitive morphologically and earlier in time than other species of t...

journal_title：Nature

authors： Andrews P,Tobien H

更新日期：1977-08-25 00:00:00

abstract：:The human B cell-specific alloantigen which is closely linked genetically to HLA contains two non-covalently associated, sialogycoprotein subunits of molecular weight (MW) 29,000 (p29), and 34,000 (p34). Although p29 and p34 have different amino-terminal sequences, their tyrosine peptide maps indicate considerable sim...

journal_title：Nature

authors： Springer TA,Kaufman JF,Terhorst C,Strominger JL

更新日期：1977-07-21 00:00:00

abstract：:Although cell adhesion to substrate must ultimately depend on 'sticking' by physical forces at the outer surface, we suggest that control is exercised through the 'grip' of the cytoskeleton. Our experiments indicate that grip can be relaxed by agents which release surface glycoproteins from some form of side-to-side o...

journal_title：Nature

authors： Rees DA,Lloyd CW,Thom D

更新日期：1977-05-12 00:00:00

abstract：:During serial structure analysis of cobaloxime derivatives, aimed at interpreting the catalytic capability of the asymmetric hydrogenation, we have found that the crystal of R-alpha-cyanoethyl (S-alpha-methylbenzylamine)-cobaloxime changes its unit cell dimensions by X-ray exposure without degradation of a single crys...

journal_title：Nature

authors： Ohashi Y,Sasada Y

更新日期：1977-05-12 00:00:00

abstract：:Cytotoxic T cells lyse only those virus infected target cells in vitro which express, in addition to the viral antigen(s), those K or D region products of the major histocompatibility complex (MHC) which were present during anti-viral sensitisation in vivo. This 'associative recognition' by cytotoxic T cells could ref...

journal_title：Nature

authors： Koszinowski U,Gething MJ,Waterfield M

更新日期：1977-05-12 00:00:00

abstract：:It has been established that many eukaryotic mRNAs contain poly(adenylic acid) tracts at their 3'-termini. The polyadenylation of mRNA occurs post-transcriptionally in the nucleus as a rapid, initial addition of 100-200 adenylate residues to the pre-mRNA (ref. 1). Subsequently, a slower chain extension (6-8 bases) of ...

journal_title：Nature

authors： Rose KM,Bell LE,Jacob ST

更新日期：1977-05-12 00:00:00

abstract：:The axial relationship between the collagen and mineral componetns in calcified turkey leg tendon was investigated using low-angle X-ray and neutron diffraction. The results indicate that the mineral is arranged with the same axial periodicity as the collagen and occupies the gap region of the collagen structure. ...

journal_title：Nature

authors： White SW,Hulmes DJ,Miller A,Timmins PA

更新日期：1977-03-31 00:00:00

abstract：:The glyceraldehyde 3-phosphate dehydogenase holoenzyme of Bacillus stearothermophilus possesses precise 222 symmetry: in this respect it differs from the reported structure of the lobster muscle enzyme. Pairs of active sites are linked through a flexible polypeptide loop which probably mediates the structural changes ...

journal_title：Nature

authors： Biesecker G,Harris JI,Thierry JC,Walker JE,Wonacott AJ

更新日期：1977-03-24 00:00:00