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排序方式: 共有1004条查询结果,搜索用时 46 毫秒
1.
Amphipyrinae have long been a catchall taxon for Noctuidae, with most members lacking discernible morphological synapomorphies that would allow their assignment to one of the many readily diagnosable noctuid subfamilies. Here data from seven gene regions (> 5500 bp) for more than 120 noctuid genera are used to infer a phylogeny for Amphipyrinae and related subfamilies. Sequence data for 57 amphipyrine genera – most represented by the type species of the genus – are examined. We present here the first large‐scale molecular phylogenetic study of Amphipyrinae and the largest molecular phylogeny of Noctuidae to date; several proposed nomenclatural changes for well‐supported results; and the identification of areas of noctuid phylogeny where greater taxon sampling and/or genomic‐scale data are needed. Adult and larval morphology, along with life‐history traits, for taxonomic groupings most relevant to the results are discussed. Amphipyrinae are significantly redefined; many former amphipyrines, excluded as a result of these analyses, are reassigned to other noctuid subfamily‐level taxa. Four genera, Chamaeclea Grote, Heminocloa Barnes & Benjamin, Hemioslaria Barnes & Benjamin and Thurberiphaga Dyar, are transferred to the tribe Chamaecleini Keegan & Wagner tribe n. in Acontiinae. Stiriina is elevated to Stiriinae rev. stat. , Grotellina is elevated to Grotellinae rev. stat. and Annaphilina is elevated to Annaphilini rev. stat. Acopa Harvey is transferred to Bryophilinae, Aleptina Dyar is transferred to Condicinae, Leucocnemis Hampson and Oxycnemis gracillinea (Grote) are transferred to Oncocnemidinae, Nacopa Barnes & Benjamin is transferred to Noctuinae and Narthecophora Smith is transferred to Stiriinae. Azenia Grote (and its subtribe Azeniina), Cropia Walker, Metaponpneumata Möschler, Sexserrata Barnes & Benjamin and Tristyla Smith are transferred to Noctuidae incertae sedis. Hemigrotella Barnes & McDunnough (formerly in subtribe Grotellina) is retained in Amphipyrinae. Argentostiria Poole and Bistica Dyar are retained in Stiriini but removed from incertae sedis position. This published work has been registered on ZooBank: http://zoobank.org/urn:lsid:zoobank.org:pub:4A140782‐31BA‐445A‐B7BA‐6EAB98ED43FA .  相似文献   
2.
When monocytes isolated from human blood adhere to glass substratum, actin- and vinculin-containing punctate plaques rapidly appear at the ventral surface of the cells. We show here that highly purified human leukocyte interferon (IFN) can inhibit formation of these adhesion plaques in a dose-dependent manner. Complete inhibition was obtained when 300 IU/ml IFN were added into the cell-seeding medium. Plaques already formed in the absence of IFN were only partially affected by subsequent addition of IFN into the culture medium. Prevention by IFN of the formation of the adhesion plaques was associated with loosened attachment of the cells to the substratum. Effect of IFN on cellular morphology was complex. At higher doses, IFN added to the cultures within 24 h of seeding almost completely inhibited the differentiation of monocytes to macrophages and most of the cells remained rounded. At lower doses, however, an enhancement of the bipolar spreading was seen and the end result was a culture with predominantly elongated fibroblastoid cells. The latter cells, unlike the fibroblastoid cells in untreated monocyte-macrophage cultures, were completely devoid of the actin plaques, while the reorganization of vimentin-type intermediate filaments took place in a normal manner. These results further support the view that the actin- and vinculin-containing plaques have a role in mediating firm adherence of human monocytes to growth substratum.  相似文献   
3.
Immunological screening of a chicken gizzard cDNA expression library was used to isolate two clones encoding a part of the non-erythroid spectrin-like protein. Clones were identified by immunoblotting of the polypeptides synthesized in Escherichia coli cells transformed with cDNA cloned in the pUC8 plasmid vector using polyclonal rabbit antibodies raised against bovine non-erythroid spectrin. The sequence of an approximately 1.5-kb cDNA insert of one clone was determined. Analysis of the predicted amino acid sequence reveals that, despite differences in immunological cross-reactivity and peptide maps, the chicken non-erythroid and the human erythrocyte spectrins are highly homologous proteins. Like the human erythrocyte spectrin, the chicken smooth muscle spectrin appears also to be constructed from repeated, homologous structures of 106 amino acid residues. This is probably a universal structure motif of spectrins.  相似文献   
4.
Computer simulations are used to predict the behavior of pollen grains with different physical properties within the acceleration field created around the ovules of the gymnosperm Ephedra trifurca. A modelling procedure is given that (1) calculates the number of pollen grains captured by an ovule's pollination-droplet and (2) gives a correlation between pollination efficiency and the physical properties (= mass, size) of different types of pollen. Based on this procedure, the number of Ephedra pollen grains captured by micropyles can be less than the number captured from other species. However, the mass and size of Ephedra pollen grains appear to coincide with those predicted to yield a local maximum of pollination efficiency, i.e. slightly larger or smaller values of either mass or size would decrease the probability of capture. In addition, the properties of Ephedra pollen grains operate synergistically in the aerodynamic environment around ovules and are focused to collide with pollination-droplets. By analogy, the properties of Ephedra pollen coincide with those predicted for a localized adaptive peak. The physical properties of pollen grain types other than E. trifurca that can maximize pollen capture are not generally represented in the aerobiology of Ephedra during the pollination season. Therefore, the phenology of pollen release, community taxonomic-composition, and the physics of particle capture play collectively important roles in the reproductive success of Ephedra trifurca.  相似文献   
5.
Immunofluorescence and immunoblotting techniques were used to study the presence and distribution of vimentin and keratin type intermediate filaments, actin, and vinculin (130 kD protein) during retinoic acid (RA)-induced differentiation of F9 embryonal carcinoma (EC) cells. The undifferentiated F9 cells regularly expressed vimentin, usually concentrated close to the nucleus, but not keratin. Actin appeared as short intracellular filaments and as spikes at the edges of the colonies, together with some diffuse cytoplasmic staining. F9 cells also showed a weak, diffuse cytoplasmic vinculin-specific fluorescence in addition to occasional small focal vinculin patches at the edges of the cell colonies. RA treatment led into a series of changes in the cytoskeletal organization of F9 cells. These changes were initiated by the appearance of distinct vinculin plaques and followed by formation of actin stress fibers and by profound changes in the organization of vimentin in the flattening cells. RA treatment finally led to the appearance and co-expression of keratin fibrils in many of the vimentin-containing F9 cells. This sequence of changes suggests that the vinculin-containing adhesion plaques may be important in the mechanism of RA-induced differentiation of EC cells.  相似文献   
6.
We have determined the nucleotide sequence coding for the chicken brain alpha-spectrin. It is derived both from the cDNA and genomic sequences, comprises the entire coding frame, 5' and 3' untranslated sequences, and terminates in the poly(A)-tail. The deduced amino acid sequence was used to map the domain structure of the protein. The alpha-chain of brain spectrin contains 22 segments of which 20 correspond to the repeat of the human erythrocyte spectrin (Speicher, D. W., and V. T. Marchesi. 1984. Nature (Lond.). 311:177-180.), typically made of 106 residues. These homologous segments probably account for the flexible, rod-like structure of spectrin. Secondary structure prediction suggests predominantly alpha-helical structure for the entire chain. Parts of the primary structure are excluded from the repetitive pattern and they reside in the middle part of the sequence and in its COOH terminus. Search for homology in other proteins showed the presence of the following distinct structures in these nonrepetitive regions: (a) the COOH-terminal part of the molecule that shows homology with alpha-actinin, (b) two typical EF-hand (i.e., Ca2+-binding) structures in this region, (c) a sequence close to the EF-hand that fulfills the criteria for a calmodulin-binding site, and (d) a domain in the middle of the sequence that is homologous to a NH2-terminal segment of several src-tyrosine kinases and to a domain of phospholipase C. These regions are good candidates to carry some established as well as some yet unestablished functions of spectrin. Comparative analysis showed that alpha-spectrin is well conserved across the species boundaries from Xenopus to man, and that the human erythrocyte alpha-spectrin is divergent from the other spectrins.  相似文献   
7.
Summary An artificial bifunctional enzyme, -glutamyl kinase/-glutamyl phosphate reductase, was obtained by fusing the Escherichia coli genes proA and proB. The proB gene was fused to the 5-end of the proA gene with a linker encoding five amino acids. When expressed in E. coli enhanced intracellular concentrations of proline were observed. At 0.6 M NaCl the growth rates for the strain carrying the fusion enzyme and a control harbouring a plasmid encoding the wild-type enzymes were 320 and 530 min, respectively.  相似文献   
8.
Summary In recent studies, the α2 chain of laminin (Ln) has been suggested to be the only laminin α chain expressed in mouse and human thymus. We have now used chain-specific monoclonal antibodies and indirect immunofluorescence microscopy to study the expression of laminin chains in samples of foetal and 6-year-old human thymus. The subepithelial basement membrane of the capsule of foetal 16- to 18-week thymus presented a bright immunoreactivity for Ln α1, α3, β1, β3 and γ1 chains but not for α2 chain, suggesting the expression of laminins-1 and-5. Most cortical and medullary epithelial cells, including Hassall's corpuscles, however, lacked laminin immunoreactivity. Immunoreactivity for Ln β2 chain was only seen in basal laminae of larger blood vessels. In thymic specimens from 6-year-old children, immunoreactivity for the laminin α1, α3, β1, β3 and γ1 chains was invariably found in subepithelial basement membrane of the capsule and that for laminin α2 chain was now also distinct but more heterogeneous. Furthermore, the thymic subepithelial basement membrane of the capsule at all stages showed immunore-activity for collagen type VII, forming the anchoring fibres in epithelial basement membranes. The subcapsular thymic epithelium also showed immunoreactivity for the BP 230 antigen and β4 integrin subunit, both components of hemidesmosomes. The present results show that the thymic subepithelial basement membrane of the capsule presents properties which are commonly seen in stratified and combined epithelia, and are compatible with suggestions of the antigenic similarity of thymic epithelial cells and keratinocytes.  相似文献   
9.
Niklas  Karl J. 《Annals of botany》1993,72(5):475-483
Perianth MP, gynoecium MG, and androecium MA dry-weight biomass(in g) of 39 species of perfect flowers was measured. Thesedata were pooled with published data from an additional 51 speciesand used to determine size-dependent variations in (MG and MA)in terms of the hypothesis that the quotient of MG and MA exceeds1·0 for out-breeding (xenogamous) species and less than1·0 for in-breeding (autogamous) species. Ordinary leastsquare regression of the pooled data (n = 90) showed MG = 0·118M0·916P (r2 = 0·884) and MA = 0·186 M0·975P(r2 = 0·865), indicating that the biomass of the gynoeciumproportionally decrease as floral size increases. The exponentsof these regressions indicate that the ratio of gynoecial toandroecial biomass decreased with increasing floral size suchthat comparatively small flowers (MP < 0·0021 g) hadMG/MA > 1·0 (predicted for 'out-breeders') while comparativelylarger flowers (MP > 0·0021 g) had MG /MA < 1·0(predicted for 'in-breeders'). Thus, on average, the type ofbreeding system was a size-dependent phenomenon. To test whether the biomass of a floral organ-type is a legitimateindicator of gender reproductive effort, the biomass (in g)of stamen filaments Mm and anther sacs MAS of 39 species wasdetermined. Least square regression of these data showed MAS= 0·188 M0·854fil (r2 = 0·967), indicatingthat species with larger stamen filaments, on the average, boreproportionally smaller anther sacs and thereby cautioning againstthe uncritical use of the allocation of biomass to floral organ-typeas a strict gauge of gender-function investment. To determine whether the loss of one gender-function resultsin proportional reallocation of biomass to the remaining gender-function,the size-dependency of androecial and gynoecial biomass wasdetermined for a total of 33 perfect and imperfect flowers ofCucumis melo. Regression of the data obtained from perfect flowersyielded MA = 0·402 M1·47P (r2 = 0·898)and MG = 4·63 M1·36P (r2 = 0·842). SinceMG/MA M0·11P , the biomass allocation to the gynoeciumrelative to the androecium decreased with increasing floralsize. This result was consistent with the broad interpecificcomparison based on 90 species with perfect flowers . Regressionof the data for imperfect flowers yielded MA = 0·151M1·02P (r2 = 0·675) and MG = 4·68 M1·47P(r2 = 0·996), indicating a near allometric relation forthe androecium and a strong positive anisometry for the gynoecium.Thus, for flowers of comparable size, a loss of female genderobtains a modest to significant again in androecial biomasswhereas the loss of male gender yields only a slight increasein gynoecial biomass. Collectively, the results of these studies indicate that biomassallocation patterns are size-dependent phenomena whose complexitieshave been largely ignored in the literature.Copyright 1993,1999 Academic Press Allometry, floral biomass, reproduction  相似文献   
10.
Fifteen petioles and rachises from three dicotyledon species(Acer saccharum, A. negundo, and Aesculus hippocastanum), apalm (Chamaedorea erumpens), and a fern (Cyrtomium falcatum)were used to test the hypothesis of 'economy in design' in termsof the design principle of uniform strength, i.e. a beam inwhich the section modulus (Z) varies along beam-length (L) inthe same proportion as the bending moment (M). Such a beam is'economical' regarding the amount of material used in its 'construction'because each of its cross section has the minimum transversearea required to satisfy the conditions of strength. The extentto which the morphology of a petiole or rachis conformed withthis design principle was initially evaluated by normalizingZ (measured at a distance, x, from the tip of a petiole or rachis)with respect to the magnitude of Z measured at the base of thepetiole. The normalized values were plotted against normalizedpetiole-rachis length (x/L). The design principle was judgedto be demonstrated when such a plot was found to be isometric,i.e. when the plot had a slope of unity. This procedure wastested further by plotting M/Z vs. x/L for representative leavesof C. erumpens and A. saccharum, and judged adequate. The allometriesof all six simple/palmate leaves were found not agree with thedesign principle. The taperings of nine petioles and rachisesfrom pinnate leaves were consistent with the design principle.This was interpreted to provide circumstantial evidence for'economy in design' in the petioles of some pinnate leaves andevidence that the mechanical 'design' of the petioles of somesimple/palmate leaves differs substantially from that of pinnateleaves.Copyright 1993, 1999 Academic Press Leaf biomechanics, plant adaptation, petioles, rachises  相似文献   
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