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61.
62.
The only known monocotylid genus to parasitise Neotropical freshwater stingrays (Potamotrygonidae) is Potamotrygonocotyle Mayes, Brooks & Thorson, 1981, a monotypic genus erected to accommodate P. tsalickisi Mayes, Brooks & Thorson, 1981. For more than 20 years, no other species has been recognised in this genus, but new efforts to survey the diversity of parasites inhabiting potamotrygonids have revealed the existence of new species and the need to redefine the genus. Here, the generic diagnosis of Potamotrygonocotyle is amended, P. tsalickisi is redescribed and four new species are recognised and described based on samples collected from the gills of freshwater potamotrygonids from the La Plata river basin: Potamotrygonocotyle chisholmae n. sp. and P. dromedarius n. sp. from Potamotrygon motoro; Potamotrygonocotyle eurypotamoxenus n. sp. from Potamotrygon cf. motoro (type-host), P. castexi, P. falkneri and P. histrix; and Potamotrygonocotyle uruguayensis n. sp. from Potamotrygon brachyura. Potamotrygonocotyle is characterised by species possessing: (1) slightly sinuous sclerotised ridges on all septa; (2) two pairs of the dorsal haptoral accessory structures associated with the four posterior peripheral loculi and with anterior dorsal haptoral accessory structure bilobate or semicircular; and (3) male copulatory organ without an accessory piece. 相似文献
63.
José Fernando Huertas-Pérez Ana M García-Campa?a Antonio González-Casado Laura Gámiz-Gracia 《Luminescence》2004,19(4):222-224
This study presents the first analytical application of the luminol chemiluminescence (CL) reaction for the sensitive detection of carbamate residues. Some experiments have been carried out to check the influence of the presence of traces of a N-methylcarbamate (carbaryl) on the CL emission produced from the oxidation of luminol using different oxidants, showing a significant enhancing effect on the CL emission when the oxidation of luminol is produced by potassium permanganate in alkaline medium, this enhancement being proportional to the carbaryl concentration. This fact has permitted the establishment of a sensitive chemiluminescence flow-injection (CL-FIA) method for the direct determination of carbaryl. The optimization of instrumental and chemical variables influencing the CL response has been carried out by applying experimental designs. Under the optimal conditions, the CL intensity was linear for a carbaryl concentration over the range 5-100 ng/mL with a detection limit of 4.9 ng/mL. This luminol-KMnO4-based FIA-CL system in basic medium shows an easy, fast and cheap alternative detection mode for the analysis of carbaryl residues in environmental water samples. 相似文献
64.
DNA vaccination can break immunological tolerance to PrP in wild-type mice and attenuates prion disease after intracerebral challenge 下载免费PDF全文
Fernandez-Borges N Brun A Whitton JL Parra B Diaz-San Segundo F Salguero FJ Torres JM Rodriguez F 《Journal of virology》2006,80(20):9970-9976
Transmissible spongiform encephalopathies (TSEs) can be ameliorated by prion protein (PrP)-specific antibodies, but active immunization is complicated by immune tolerance to the normal cellular host protein (PrP(C)). Here, we show that DNA immunization of wild-type mice can break immune tolerance against the prion protein, resulting in the induction of PrP-specific antibody and T-cell responses. PrP immunogenicity was increased by fusion to the lysosomal targeting signal from LIMPII (lysosomal integral membrane protein type II). Although mice immunized with a PrP-LIMPII DNA vaccine showed a dramatic delay in the onset of early disease signs after intracerebral challenge, immunization against PrP also had some deleterious effects. These results clearly confirm the feasibility of using active immunization to protect against TSEs and, in the absence of effective treatments, indicate a suitable alternative for combating the spread of these diseases. 相似文献
65.
Boron deficiency causes accumulation of chlorogenic acid and caffeoyl polyamine conjugates in tobacco leaves 总被引:5,自引:0,他引:5
Camacho-Cristóbal JJ Lunar L Lafont F Baumert A González-Fontes A 《Journal of plant physiology》2004,161(7):879-881
The effects of boron (B) deficiency on carbohydrate concentrations and the pattern of phenolic compounds were studied in leaves of tobacco plants (Nicotiana tabacum L.). Plants grown under B deficiency showed a notable increase in leaf carbohydrates and total phenolic compounds when compared to controls. The qualitative composition of phenolics was analyzed by HPLC-mass spectrometry. The level of caffeate conjugates (i.e., chlorogenic acid) increased in B-deficient plants. In addition, the accumulation of two caffeic acid amides (N-caffeoylputrescine and putative dicaffeoylspermidine) was observed. 相似文献
66.
Galanter JM Fernandez-Lopez JC Gignoux CR Barnholtz-Sloan J Fernandez-Rozadilla C Via M Hidalgo-Miranda A Contreras AV Figueroa LU Raska P Jimenez-Sanchez G Zolezzi IS Torres M Ponte CR Ruiz Y Salas A Nguyen E Eng C Borjas L Zabala W Barreto G González FR Ibarra A Taboada P Porras L Moreno F Bigham A Gutierrez G Brutsaert T León-Velarde F Moore LG Vargas E Cruz M Escobedo J Rodriguez-Santana J Rodriguez-Cintrón W Chapela R Ford JG Bustamante C Seminara D Shriver M Ziv E Burchard EG Haile R 《PLoS genetics》2012,8(3):e1002554
Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R2 > 0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region. 相似文献
67.
Kofoidinium, Spatulodinium and other kofoidiniaceans (Noctilucales, Dinophyceae) in the Pacific Ocean 总被引:1,自引:0,他引:1
Examples of rarely reported dinoflagellates of the family Kofoidiniaceae F.J.R. Taylor (Noctilucales) from the northwest, equatorial and southeast Pacific Ocean are described and illustrated. Kofoidinium was the most ubiquitous genus with a maximum abundance of 10 cells L(-1). Specimens of this genus were identified to four species: Kofoidinium sp. that showed a pointed extension that emerges from the antero-ventral region and K. velelloides, both of which had diameters that ranged from 40 to 200 microm; Kofoidinium pavillardii which showed a rounded epitheca and a larger size (approximately 300-700 microm in diameter); and another species, tentatively identified as K. splendens, that contained red circular inclusions. Further research is needed to clarify the characteristics that separate K. splendens from the other species. This study is the first to record the genus Spatulodinium in tropical waters and in the southern hemisphere. S. cf. pseudonoctiluca was found in the southeast Pacific Ocean, as well as other smaller specimens with a different shape or disposition of the tentacle that may belong to two other species. In the northwest and equatorial Pacific, specimens of Spatulodinium showed a green pigmentation that suggested the existence of the first species known in the order Noctilucales to contain its own chloroplasts. Immature stages of kofoidiniaceans, some containing symbiotic microalgae, are illustrated, as well as mature stages related to Pomatodinium and to unknown genera of kofoidiniaceans. Kofoidiniaceans are shown to be common and widely distributed in the Pacific, and are probably also frequent in other oceans, but are rarely recognised. 相似文献
68.
Roman Zoss Fernando Medina Ferrer Beverly E. Flood Daniel S. Jones Deon.C. Louw Jake Bailey 《Geobiology》2019,17(1):76-90
The processes that lead to the precipitation of authigenic calcium phosphate minerals in certain marine pore waters remain poorly understood. Phosphogenesis occurs in sediments beneath some oceanic upwelling zones that harbor polyphosphate‐accumulating bacteria. These bacteria are believed to concentrate phosphate in sediment pore waters, creating supersaturated conditions with respect to apatite precursors. However, the relationship between microbes and phosphorite formation is not fully resolved. To further study this association, we examined microbial community data generated from two sources: sediment cores recovered from the shelf of the Benguela upwelling region where phosphorites are currently forming, and DNA preserved within phosphoclasts recovered from a phosphorite deposit along the Benguela shelf. iTag and clone library sequencing of the 16S rRNA gene showed that many of our sediment‐hosted communities shared large numbers of phylotypes with one another, and that the same metabolic guilds were represented at localities across the shelf. Sulfate‐reducing bacteria and sulfur‐oxidizing bacteria were particularly abundant in our datasets, as were phylotypes that are known to carry out nitrification and the anaerobic oxidation of ammonium. The DNA extracted from phosphoclasts contained the signature of a distinct microbial community from those observed in the modern sediments. While some aspects of the modern and phosphoclast communities were similar, we observed both an enrichment of certain common microbial classes found in the modern phosphogenic sediments and a relative depletion of others. The phosphoclast‐associated DNA could represent a relict signature of one or more microbial assemblages that were present when the apatite or its precursors precipitated. While these taxa may or may not have contributed to the precipitation of the apatite that now hosts their genetic remains, several groups represented in the phosphoclast extract dataset have the genetic potential to metabolize polyphosphate, and perhaps modulate phosphate concentrations in pore waters where carbonate fluorapatite (or its precursors) are known to be precipitating. 相似文献
69.
Fernando ngel Fernndezlvarez Marc Farr Antoni SnchezMrquez Roger Villanueva Oscar Escolar Joan Navarro 《Ecology and evolution》2020,10(23):12685
Larval mortality is a keystone ecological factor for many benthic octopus since it mostly occurs before their settlement in the sea bottom as benthic juveniles. The literature had revealed that records of adult animals with morphological abnormalities (teratologies) are fewer in species with complex life cycle than in those with direct development. This is a direct consequence of the morphological, physiological, and development challenges that the transition from the larval to the adult morphology represents. During a routine fishing sample, we found an immature female horned octopus with additional buccal structures in two suckers of its ventral arms, likely rendering these suckers as inefficient. Based on the literature about the natural history of octopus, we provide evidence that these abnormalities were present at the moment of hatch. We evaluated the impact of the teratologies by comparing the shape of the buccal beaks and the trophic niche of the individual with five normal conspecifics. Although the beaks showed a different shape than normal individuals, the trophic niche was similar. Surprisingly, the teratological condition of the individual likely had no severe impacts on its life, even though it likely represents a handicap for its survival during its planktonic life. We also comment on other previous records from the literature of teratological adult octopus to highlight the amazing adaptive capacity of octopus to deal with challenging morphologies. 相似文献
70.
María de Lourdes Moreno María Teresa García Antonio Ventosa Fernando Iglesias-Guerra Encarnación Mellado 《Systematic and applied microbiology》2010
The extremely halophilic bacterium strain IC10 was isolated from a solar saltern on Isla Cristina (southern Spain). Phylogenetic, genotypic and phenotypic data supported the inclusion of this strain in the species Salicola marasensis. An analysis of intracellular organic osmotic solutes showed glycine betaine to be present, contributing to the overall osmotic balance, and this was the only compatible solute accumulated when S. marasensis IC10 was grown over a wide range of external NaCl concentrations (10–25%, w/v). 相似文献