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Endemic atyids of southern Europe have been ascribed to Dugastella, and to subterranean Typhlatya and Troglocaris: Dugastella is epigean, and Typhlatya and Troglocaris are subterranean. An extensive collection from all centres of distribution in southern Europe (excepting the Caucasus) was morphologically examined. A taxonomic redefinition of the group, at different levels, is based on recently published and newly generated molecular phylogeny, whereas newly established taxa have also been morphologically defined. The accordance between the phylogenetic tree and the geographical distributions suggested that a re‐evaluation of some traditionally used morphological characters should generate the most parsimonious solution: this enabled a novel taxonomic division. Gallocaris gen. nov. is erected for the French Troglocaris inermis Fage, 1937, which is more closely related to the epigean Dugastella valentina (Ferrer Galdiano, 1924) than to its supposed congeners. Both western Mediterranean Typhlatya species are closely related to their Caribbean congeners. All other European cave shrimps constitute a monophylum, Troglocaris, which is divisible into subgenera (already with available names): the holo‐Dinaric Troglocaris (Troglocaris) Dormitzer, 1853, south‐eastern mero‐Dinaric Troglocaris (Troglocaridella) Babi?, 1922, and Troglocaris (Spelaeocaris) Matja?i?, 1956, and the Caucasian Troglocaris (Xiphocaridinella) Sadovsky, 1930. Four new species are described: Troglocaris (Troglocaris) bosnica sp. nov. , Troglocaris (Spelaeocaris) prasence sp. nov. , Troglocaris (Spelaeocaris) kapelana sp. nov. , and Troglocaris (Spelaeocaris) neglecta sp. nov. The distribution of all established species is shown, and the value of the morphological characters is discussed. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 786–818. 相似文献
53.
CONSUELO SENDINO KAMIL ZÁGORŠEK PAUL D. TAYLOR 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2012,45(3):423-431
Sendino, C., Zágor?ek, K. & Taylor, P.D. 2012: Asymmetry in an Ordovician conulariid cnidarian. Lethaia, Vol. 45, pp. 423–431. Conulariids are fossils of the presumed polyps of an extinct scyphozoan cnidarian group. Their cone‐shaped skeletons normally show perfect tetraradial symmetry. However, in the Ordovician species Metaconularia anomala ( Barrande 1867 ) from Drabov (Czech Republic), tetraradial symmetry is compromised in three ways: (1) the skeleton often shows torsion; (2) the four sides may vary in width at the same level within one individual; and (3) one side may be deleted to give a triradial skeleton. Almost 2000 specimens were studied in museum collections. About 56% of analysed specimens are twisted in an anticlockwise direction (sinistral) when viewed from the apex towards the aperture, 28% show no torsion, 1% exhibit clockwise torsion (dextral) and the remaining 15% cannot be classified. Maximum measured torsion rate was 1.5°/mm. A significant negative correlation between torsion rate and length suggests that more highly torted individuals may have survived less well. Almost 5% of individuals show loss of one side for at least part of their lengths. Although many individuals have four sides of equal width, in a significant proportion the sides are of unequal width, up to a maximum/minimum side width ratio of 2 (i.e. widest face twice the width of the narrowest). In the absence of a satisfactory taphonomic model to explain the asymmetries, they are regarded as mirroring asymmetries in the living conulariids, with the strong preference for sinistral torsion interpreted as an example of a fixed asymmetry that was genetically controlled and heritable. It is speculated that the signalling protein Nodal as well as Hox‐like genes were involved in controlling the asymmetries described in M. anomala. 相似文献
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RADIM J. VAUT PETER J. VAN DIJK MATTHIEU FALQUE BOHUMIL TRVNÍEK J. HANS DE JONG 《Molecular ecology resources》2004,4(4):645-648
This study aims at developing and characterizing new microsatellite primer pairs in Taraxacum officinale auct. to produce polymorphic markers for genetical and evolutionary studies on apomixis in this sexual‐apomictic complex. A total of 24 diploid plants were tested for allelic polymorphism and heterozygosity. Out of nine loci three deviated significantly from the Hardy–Weinberg equilibrium expectations, probably due to the presence of null‐alleles. Successful cross‐species amplification was obtained for all markers in 29 Taraxacum microspecies from five sections. 相似文献
56.
MARTIN FIKÁČEK ALEXANDER PROKIN ROBERT B. ANGUS ALEXANDER PONOMARENKO YANLI YUE DONG REN JAKUB PROKOP 《Systematic Entomology》2012,37(3):420-447
We performed a phylogenetic analysis focused on the hydrophiloid family Helophoridae (Coleoptera: Polyphaga) in order to test the phylogenetic position of selected Mesozoic fossils assigned to the Hydrophiloidea. The analysis is based on 92 characters of larvae and adults, and includes all extant subgenera of Helophorus and representatives of all other extant hydrophiloid families. Based on this analysis, we provide additional evidence for the monophyly of the helophorid lineage containing the families Helophoridae, Georissidae and Epimetopidae, as well as the first hypothesis on the phylogenetic relationships within Helophorus, revealing three main clades: Lihelophorus, Rhopalohelophorus and the clade of sculptured small subgenera; the subgenera Helophorus s.str., Gephelophorus, Trichohelophorus and Transithelophorus are recognized as paraphyletic or polyphyletic. Inclusion of fossil species in the analysis reveals the Mesozoic genera Hydrophilopsia Ponomarenko, Laetopsia Fiká?ek et al. (adult forms) and Cretotaenia Ponomarenko (larval form) as basal extinct clades of the helophorid lineage, the former genus Mesosperchus Ponomarenko as containing probable stem taxa of Helophorus and the former genus Mesohelophorus Ponomarenko as a member of the Helophorus clade containing extant sculptured subgenera. The extant subgenus Thaumhelophorus syn.nov. is synonymized with Rhopalohelophorus. Our results show that the family Helophoridae may be dated back to the late Jurassic (c. 150 Ma) and the extant clades of Helophorus back to the Early Cretaceous (c. 136 Ma). The basal groups of Helophorus and the supposed basal extinct lineages of the helophorid lineages are shown to be aquatic as adults. A single origin of trichobothria and ventral hydrophobic pubescence in the common ancestor of the Hydrophiloidea is hypothesized, indicating ancestral aquatic habits in the adult stage for the whole Hydrophiloidea. 相似文献
57.
J. POKORNÁ K. SCHWARZEROVÁ S. ZELENKOVÁ J. PETRÁEK I. JANOTOVÁ V. APKOVÁ & Z. OPATRNÝ 《Plant, cell & environment》2004,27(5):641-653
Cytoskeletal proteins assemble into dynamic polymers that play many roles in nuclear and cell division, signal transduction, and determination of cell shape and polarity. The distribution and dynamics of microtubules (MTs) and actin filaments (AFs) are determined, among other factors, by the location of their nucleation sites. Whereas the sites of microtubule nucleation in plants are known to be located under the plasma membrane and on the nuclear envelope during interphase, there is a striking lack of information about nucleation sites of AFs. In the studies reported herein, low temperature (0 °C) was used to de‐polymerize AFs and MTs in tobacco BY‐2 (Nicotiana tabacum L.) cells at interphase. The extent of de‐polymerization of cytoskeletal filaments in interphase cells during cold treatment and the subcellular distribution of nucleation sites during subsequent recovery at 25 °C were monitored by means of fluorescence microscopy. The results show that AFs re‐polymerized rapidly from sites located in the cortical region and on the nuclear envelope, similarly to the initiation sites of MTs. In contrast to MTs, however, complete reconstitution of AFs was preceded by the formation of transient actin structures including actin dots, rods, and filaments with a dotted signal. Immunoblotting of soluble and sedimentable protein fractions showed no changes in the relative amounts of free and membrane‐bound actin or tubulin. 相似文献
58.
Background
Sputum microscopy is the only diagnostic for tuberculosis (TB) available at peripheral levels of health service in resource-poor countries. Its sensitivity is reduced in high HIV-prevalence settings. Sodium hypochlorite (NaOCl) specimen sedimentation prior microscopy and light-emitting diode (LED)-fluorescence microscopy (FM) can individually improve performance of microscopy. This study aimed to evaluate the performance of combined LED-FM and NaOCl sputum sedimentation for TB detection at peripheral level of health services.Methods
A prospective study was conducted in an urban health clinic in Nairobi, Kenya. Three sputum specimens were collected over 2 days from consecutive TB suspects. Smears were prepared and stained with auramine O and Ziehl-Neelsen (ZN) methods. Bleach (3.5%) was added to the remaining specimen before overnight sedimentation at room temperature. Auramine O staining was performed on smears of sediment. A 4th specimen was collected for TB culture. Auramine smears were read under the same microscope as used for ZN smears, but equipped with the LED FluoLED™ fluorescence illuminator.Results
497 patients were included, and 1394 specimens collected. The yield of positive specimen was significantly increased after NaOCl sedimentation (24.9%) compared to direct LED-FM (20.6%) and direct ZN (20.3%). In detecting smear-positive patients, sensitivity was 78.5% for LED-FM after NaOCl sedimentation compared to 73.2% and 72.0% for direct LED-FM (P = 0.06) and direct ZN (P = 0.06), respectively. Specificity was 87.8% for LED-FM after NaOCl sedimentation compared to 96.7% and 95.9% for direct LED-FM (P<0.01) and direct ZN (P<0.01), respectively. Inter-reading agreement (kappa = 0.7) and technicians'' acceptability were good.Conclusion
NaOCl sedimentation did not improve the performance of LED-FM in the diagnosis of pulmonary TB at peripheral health service level. 相似文献59.
PHYTOALEXIN DEFICIENT 4 affects reactive oxygen species metabolism,cell wall and wood properties in hybrid aspen (Populus tremula L. × tremuloides)
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IRENEUSZ ŚLESAK MAGDALENA SZECHYŃSKA‐HEBDA HALINA FEDAK NATALIA SIDORUK JOANNA DĄBROWSKA‐BRONK DAMIAN WITOŃ ANNA RUSACZONEK ANDRZEJ ANTCZAK MICHAŁ DROŻDŻEK BARBARA KARPIŃSKA STANISŁAW KARPIŃSKI 《Plant, cell & environment》2015,38(7):1275-1284
The PHYTOALEXIN DEFICIENT 4 (PAD4) gene in Arabidopsis thaliana (AtPAD4) is involved in the regulation of plant – pathogen interactions. The role of PAD4 in woody plants is not known; therefore, we characterized its function in hybrid aspen and its role in reactive oxygen species (ROS)‐dependent signalling and wood development. Three independent transgenic lines with different suppression levels of poplar PAD expression were generated. All these lines displayed deregulated ROS metabolism, which was manifested by an increased H2O2 level in the leaves and shoots, and higher activities of manganese superoxide dismutase (MnSOD) and catalase (CAT) in the leaves in comparison to the wild‐type plants. However, no changes in non‐photochemical quenching (NPQ) between the transgenic lines and wild type were observed in the leaves. Moreover, changes in the ROS metabolism in the pad4 transgenic lines positively correlated with wood formation. A higher rate of cell division, decreased tracheid average size and numbers, and increased cell wall thickness were observed. The results presented here suggest that the Populus tremula × tremuloides PAD gene might be involved in the regulation of cellular ROS homeostasis and in the cell division – cell death balance that is associated with wood development. 相似文献
60.
David EK Ferrier 《BMC biology》2011,9(1):3
The phylum to which humans belong, Chordata, takes its name from one of the major shared derived features of the group, the
notochord. All chordates have a notochord, at least during embryogenesis, and there is little doubt about notochord homology
at the morphological level. A study in BMC Evolutionary Biology now shows that there is greater variability in the molecular genetics underlying notochord development than previously appreciated. 相似文献