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51.
Cyclic nucleotide injection in neurons shows that cAMP controls a new type of membrane permeability. The neuron response to cAMP has a short delay, unusual bioenergetics and is blocked by drugs binding with the regulatory subunit of protein kinase. These data are interpreted in terms of the hypothesis that the controlling system of the living cell is a molecular (DNA, RNA, protein operators with complementary addresses), holographic (quick changeable lattice--cytoskeleton), quantum (each phonon examines whole lattice), hypersound (with wave length 100-10,000 A that does not destroy molecules) system with an inner point of view (molecular coding of questions and answers about quantum processing). Neither an electron, nor a macroscopic computer has an inner point of view.  相似文献   
52.
Russian Journal of Genetics - Polymorphic variants of genes of enzymes of xenobiotic biotransformation (CYP1A1 (rs4646903), CYP1A2 (rs762551), CYP2D6 (rs35742686), CYP2E1 (rs2031920), EPHX1...  相似文献   
53.
Arabidopsis thaliana At-4/1 is the protein of unknown function capable of polar localization in plant cells and intercellular trafficking. In this work, we cloned cDNAs and chromosomal genes of At-4/1 orthologues from several Nicotiana species. Similarly to the 4/1 genes of A. thaliana and Oryza sativa, Nicotiana 4/1 genes have eight exons and seven introns but are considerably longer due to their larger introns. The allotetraploid genome of Nicotiana tabacum, which is known to consist of the ‘S genome’ originated from Nicotiana sylvestris and the ‘T genome’ derived from Nicotiana tomentosiformis, encodes two 4/1 genes. The T genome-encoded 4/1 gene, but not that of the S genome, contains a SINE-like transposable element in its intron 2. The 4/1 genes of Nicotiana hesperis and Nicotiana benthamiana lack such an element in the intron 2, but possess a related SINE-like sequence in their intron 4. Collectively, the sequence analysis data provide an insight into the organization of 4/1 genes in flowering plants and the patterns of evolution in the genus Nicotiana. The Nicotiana 4/1 proteins and those of other flowering plants show a significant level of sequence similarity. Computer-assisted analysis was further used to compare their predicted secondary structures. Several algorithms confidently predicted the presence of several coiled-coil domains occupying similar positions in different 4/1 proteins. Analysis of circular dichroism spectra carried out for bacterially expressed N. tabacum 4/1 protein (Nt-4/1) and its N- and C-terminally truncated mutants confirmed that the secondary structure of Nt-4/1 is generally alpha-helical. The C-terminal region of Nt-4/1 was found to undergo a partial proteolysis in Escherichia coli cells. Differential scanning calorimetry of Nt-4/1 protein and its mutants revealed three calorimetric domains most probably corresponding to the N-terminal, central, and C-terminal structural domains of the protein.  相似文献   
54.
The review considers the function of the important chromosome regions telomeres in normal and immortal cells. Telomeres are dynamic nucleoprotein structures that cap the ends of eukaryotic chromosomes, protecting them from degradation and end-to-end fusion. The functional state of telomeres depends on many interrelated parameters such as telomerase activity, the status of the telomere safety complex shelterin, and telomere-associated proteins (replication, recombination, DNA break repair factors, etc.). Special attention is paid to the mechanisms that control the telomere length in normal and immortal cells as well as in cells containing or lacking active telomerase. The features attributed to an alternative telomere length control are analyzed, in particular, in view of a recently discovered additional mechanism of telomere shortening by t-cycle trimming. The possibility of expressing both telomerase-dependent and recombinational pathways of telomere length control in normal mammalian cells is considered, as well as the role of shelterin proteins in choosing one of them to be dominant. The review additionally discusses the role of telomeres in the spatial organization of the nucleus during mitosis and meiosis and specific telomere organizations in mammals, including Iberian shrews with their unusual or rare chromosome structures.  相似文献   
55.
Uncouplers of oxidative phosphorylation increased the speed of substrate oxidation and ATP hydrolysis and raised cAMP induced neuron membrane current. Different inhibitors decreased it. Both effects support the hypothesis that a signal of intracellular injected cAMP spreads to the neuron membrane as a mechanical signal. This signal propagated to the membrane along microtubules which according to this hypothesis serve as a sound generator with metabolic heat pumping.  相似文献   
56.
Drugs preventing cAMP interaction with regulatory subunit of cAMP-dependent protein kinase, tolbutamide and db-cAMP injected into neurons of Helix lucorum decreased the cell response to cAMP, but H-8-a potent inhibitor of this enzyme catalytic subunit did not produce such effect. It is suggested that the neuron electric response to cAMP injection is not caused by protein phosphorylation.  相似文献   
57.
Embryogenesis of Payer's patches (PP) of the ileum, has been studied in 183 human fetuses 8-40-week-old. Their anlages appear on the 8th-9th week as an accumulation of atypical villi. At first the PP are localized in the cranial part of the ileum, and then spread caudally. Their most active increase in amount takes place from the 15th up to 17th weeks of development. From the 8th up to the 40th weeks the PP amount increase from 10 up to 37. During the same time their length develops from 0.7 up to 8.3 mm, their width--from 0.3 up to 2.2. The first lymphoid nodules++ in the PP are detected on the 14th week, then their number rises from 200 up to 3,500. The superficial area of all the PP, turning into the lumen of the ileum widens from 1.4 up to 620 mm2. Their predominate form is ellipsoid. During the whole prenatal period in the lymphoid nodules++ no germinative centers are revealed. Lymphocytes in the PP are identified in 8-9-week-old fetuses. By the 29th week the whole amount of lymphocytes in them increase up to 9.6 x 10(6) cells. Lymphocytic suspension of the PP of 8-9-week-old fetuses contains 1.7% of T-lymphocytes (E = POK) and 0.1% of B-lymphocytes (EAC = POK). By the 29th week their amount increases up to 9% and 7%, respectively, but by birth it does not reach their amount in the PP of mature organisms.  相似文献   
58.
A FISH with a probe for telomeric and rDNA repeats and immunofluorescence with ANA CREST and antibodies to nucleolae protein B23 were used to study the three-dimensional (3D) organization of fibroblast interphase nuclei in two shrew twin species, Sorex granarius and Sorex araneus, of the Cordon race. Karyotypes of these species are composed of nearly identical chromosomal arms and differ in the number of their metacentrics and the structures of their terminal chromosome regions. In the short arms of S. granarius, 32 of the acrocentrics have large telomeres that contain an average of 218 kb telomere repeats, which alternate with ribosomal repeats. These regions also contain active nucleolar organizing regions (NORs). In contrast, in active NORs in S. araneus are localized at the terminal regions of 8 chromosomal arms (Zhdanova et al., 2005; 2007b). Here, we show that associations of chromosomes by telomeres and the contact of a part of the telomere clusters with the inner nuclear membrane and nucleolus characterize the interphase nuclei of both Sorex granarius and Sorex araneus. We also reveal the partial colocalization of telomere and ribosomal clusters and the spatial proximity of centomeric and telomeric regions in the interphase nuclei of S. granarius. It appears that only ribosomal clusters containing a sufficient number of active ribosomal genes exhibit a connection with the nucleolus. Nucleolus disassembly during the fibroblastís transition to mitosis and the role of the B23 protein in this process have been studied.  相似文献   
59.
Disturbed fibroblast growth factor (Fgf) and transforming growth factor beta (Tgfbeta) signaling lead to a variety of human skeletal disorders. To reveal the possible function and interaction of these signaling systems we have started to analyze the expression patterns of signaling factors, antagonists, receptors and transducers of these pathways in forelimbs of mouse embryos and compared them to the expression of established markers including Ihh. In addition to defining their expression domains in the developing bone, our study identified new subpopulations of chondrocytes characterized by the expression of distinct combinations of markers.  相似文献   
60.
Autonomous modes of behavior in primordial germ cell migration   总被引:2,自引:0,他引:2  
Zebrafish primordial germ cells (PGCs) are guided toward their targets by the chemokine SDF-1a. PGCs were followed during three phases of their migration: when migrating as individual cells, while remaining in a clustered configuration, and when moving as a cell cluster within the embryo. We found that individually migrating PGCs alternate between migratory and pausing modes. Pausing intervals are characterized by loss of cell polarity and correlate with subsequent changes in the direction of migration. These properties constitute an intrinsic behavior of PGCs, enabling erasure of prior polarity and re-sampling of the environment. Following migration arrest at a site of high SDF-1a levels, PGCs resume migration as a cluster. The seemingly coordinated cluster migration is a result of single-cell movement in response to local variations in SDF-1a distribution. Together, these behavioral modes allow the cells to arrive at specific destinations with high fidelity and remain at their target site.  相似文献   
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