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1.
Reviewing published coccinellid surveys we found that the number of adventive species has increased steadily over the last
century while the average proportion of native individuals has remained fairly constant until 1987 followed by a rapid decrease
between 1987 and 2006. Seven long-term studies indicated that the total density of coccinellids increased by an average of
14% following establishment of adventive species, but this increase was not significant and in 4 of 7 cases the total density
of coccinellids actually decreased following establishment. Similarly, no significant difference was found in comparisons
of diversity across all studies. These results illustrate that even with multiple long-term data sets it is currently difficult
to make any general conclusions regarding the impact adventive coccinellids have had on native coccinellid assemblages. However,
it is clear that specific systems and species have seen major shifts in recent years. For example, adventives have become
the dominant species in a third of the assemblages where they are found. Focusing on two formerly common native species, Adalia bipunctata and Coccinella novemnotata, we show they have become rare in their former ranges and discuss potential explanations for this phenomenon. 相似文献
2.
GM1 Ganglioside: In Vivo and In Vitro Trophic Actions on Central Neurotransmitter Systems 总被引:1,自引:0,他引:1
Abstract: There is now substantial evidence that GM1 ganglioside is effective in partially correcting the consequences of neuroinjury in a number of in vivo and in vitro model systems. Although the molecular mechanism(s) and the substrates for the neurotrophic activity of the gangliosides are not fully understood, the published experimental work suggests that GM1 has antineurotoxic, neuroprotective, and neurorestorative effects on various central neurotransmitter systems. This review focuses attention on studies reporting that GM1 restores neuronal integrity and function in the brain of lesioned young as well as aged animals. Critical analysis of these studies can provide guidance for future ganglioside research and may point to novel approaches for treating neuroinjury and a variety of degenerative conditions, including aging. 相似文献
3.
Kate Buchacz Miao-Jung Chen Maree Kay Parisi Maya Yoshida-Cervantes Erin Antunez Viva Delgado Nicholas J. Moss Susan Scheer 《PloS one》2015,10(3)
Background
Persons with unsuppressed HIV viral load (VL) who disengage from care may experience poor clinical outcomes and potentially transmit HIV. We assessed the feasibility and yield of using the San Francisco Department of Public Health (SFDPH) enhanced HIV surveillance system (eHARS) to identify and re-engage such persons in care.Methods
Using SFDPH eHARS data as of 4/20/2012 (index date), we selected HIV-infected adults who were alive, had no reported VL or CD4 cell count results in the past nine months (proxy for “out-of-care”) and a VL >200 copies/mL drawn nine to 15 months earlier. We prioritized cases residing locally for investigation, and used information from eHARS and medical and public health databases to contact them for interview and referral to the SFDPH linkage services (LINCS). Twelve months later, we matched-back to eHARS data to assess how HIV laboratory reporting delays affected original eligibility, and if persons had any HIV laboratory results performed and reported within 12 months after index date (‘new labs’).Results
Among 434 eligible persons, 282 were prioritized for investigation, of whom 75 (27%) were interviewed, 79 (28%) could not be located, and 48 (17%) were located out of the area. Among the interviewed, 54 (72%) persons accepted referral to LINCS. Upon match-back to eHARS data, 324 (75%) in total were confirmed as eligible, including 221 (78%) of the investigated; most had new labs.Conclusions
Among the investigated persons presumed out-of-care, we interviewed and offered LINCS referral to about one-quarter, demonstrating the feasibility but limited yield of our project. Matching to updated surveillance data revealed that a substantial minority did not disengage from care and that most re-engaged in HIV care. Verifying persons’ HIV care status with medical providers and improving timeliness of transfer and cross-jurisdictional sharing of HIV laboratory data may aid future efforts. 相似文献4.
Effects of oxidative and nitrative challenges on alpha-synuclein fibrillogenesis involve distinct mechanisms of protein modifications 总被引:7,自引:0,他引:7
Norris EH Giasson BI Ischiropoulos H Lee VM 《The Journal of biological chemistry》2003,278(29):27230-27240
Filamentous inclusions of alpha-synuclein protein are hallmarks of neurodegenerative diseases collectively known as synucleinopathies. Previous studies have shown that exposure to oxidative and nitrative species stabilizes alpha-synuclein filaments in vitro, and this stabilization may be due to dityrosine cross-linking. To test this hypothesis, we mutated tyrosine residues to phenylalanine and generated recombinant wild type and mutant alpha-synuclein proteins. alpha-Synuclein proteins lacking some or all tyrosine residues form fibrils to the same extent as the wild type protein. Tyrosine residues are not required for protein cross-linking or filament stabilization resulting from transition metal-mediated oxidation, because higher Mr SDS-resistant oligomers and filaments stable to chaotropic agents are detected using all Tyr --> Phe alpha-synuclein mutants. By contrast, cross-linking resulting from exposure to nitrating agents required the presence of one or more tyrosine residues. Furthermore, tyrosine cross-linking is involved in filament stabilization, because nitrating agent-exposed assembled wild type, but not mutant alpha-synuclein lacking all tyrosine residues, was stable to chaotropic treatment. In addition, the formation of stable alpha-synuclein inclusions in intact cells after exposure to oxidizing and nitrating species requires tyrosine residues. These findings demonstrate that nitrative and/or oxidative stress results in distinct mechanisms of alpha-synuclein protein modifications that can influence the formation of stable alpha-synuclein fibrils. 相似文献
5.
Jonathan Gottschall Rachel Berkey Mitchell Cawson Carly Drown Matthew Fleischner Melissa Glotzbecker Kimberly Kernan Tyler Magnan Kate Muse Celeste Ogburn Stephen Patterson Christopher Skeels Stephanie St. Joseph Shawna Weeks Alison Welsh Erin Welch 《Human nature (Hawthorne, N.Y.)》2003,14(4):365-382
Literary scholars are generally suspicious of the concept of universals: there are presently no candidates for literary universals
that a high proportion of literary scholars would accept as valid. This paper reports results from a content analysis of patterns
of characterization in folktales from 48 culture areas, aimed at identifying patterns of characterization that apply across
regions of the world and levels of cultural complexity. The search for these patterns was guided by evolutionary theory and
the findings are consistent with previous research on patterns of altruism, sex differences in mate preferences, sex differences
in reproductive strategy, and differing emphases on male and female physical attractiveness. World literature, especially
originally oral literature, represents a vast and neglected repository of information that researchers can use to more precisely
map the contours of human nature.
Jonathan Gottschall received his Ph.D. in English from Binghamton University and now teaches at St. Lawrence University in
Canton, New York. His research focuses on integrating Darwinian approaches to human behavior and psychology with literary
studies. The other authors are undergraduate students at St. Lawrence University. 相似文献
6.
7.
Sabine Tausz‐Posch Robert M. Norton Saman Seneweera Glenn J. Fitzgerald Michael Tausz 《Physiologia plantarum》2013,148(2):232-245
This study evaluates whether the target breeding trait of superior leaf level transpiration efficiency is still appropriate under increasing carbon dioxide levels of a future climate using a semi‐arid cropping system as a model. Specifically, we investigated whether physiological traits governing leaf level transpiration efficiency, such as net assimilation rates (Anet), stomatal conductance (gs) or stomatal sensitivity were affected differently between two Triticum aestivum L. cultivars differing in transpiration efficiency (cv. Drysdale, superior; cv. Hartog, low). Plants were grown under Free Air Carbon dioxide Enrichment (FACE, approximately 550 µmol mol?1 or ambient CO2 concentrations (approximately 390 µmol mol?1). Mean Anet (approximately 15% increase) and gs (approximately 25% decrease) were less affected by elevated [CO2] than previously found in FACE‐grown wheat (approximately 25% increase and approximately 32% decrease, respectively), potentially reflecting growth in a dry‐land cropping system. In contrast to previous FACE studies, analyses of the Ball et al. model revealed an elevated [CO2] effect on the slope of the linear regression by 12% indicating a decrease in stomatal sensitivity to the combination of [CO2], photosynthesis rate and humidity. Differences between cultivars indicated greater transpiration efficiency for Drysdale with growth under elevated [CO2] potentially increasing the response of this trait. This knowledge adds valuable information for crop germplasm improvement for future climates. 相似文献
8.
The purification of glyoxalase I (S-lactoyl-glutathione methylglyoxal-lyase (isomerizing) EC 4.4.1.5) from DBA/1J mouse liver employing ion exchange and affinity chromatography is described. The enzyme was purified 1140-fold and it exhibits a specific activity of 2200 units/mg of protein. The activity was determined to be homogeneous by sedimentation velocity and sedimentation equilibrium ultracentrifugation and by polyacrylamide electrophoresis. The molecular weight is approimately 43 000 and the sedimentation coefficient is 3.4 S. Kinetic data are consistent with a one-substrate (hemimercaptal) reaction mechanism but do not rule out alternate branches at low substrate and free glutathione concentrations. 相似文献
9.
Li B Cardinale SC Butler MM Pai R Nuss JE Peet NP Bavari S Bowlin TL 《Bioorganic & medicinal chemistry》2011,19(24):7338-7348
Botulinum neurotoxins (BoNTs) are the most lethal of biological substances, and are categorized as class A biothreat agents by the Centers for Disease Control and Prevention. There are currently no drugs to treat the deadly flaccid paralysis resulting from BoNT intoxication. Among the seven BoNT serotypes, the development of therapeutics to counter BoNT/A is a priority (due to its long half-life in the neuronal cytosol and its ease of production). In this regard, the BoNT/A enzyme light chain (LC) component, a zinc metalloprotease responsible for the intracellular cleavage of synaptosomal-associated protein of 25 kDa, is a desirable target for developing post-BoNT/A intoxication rescue therapeutics. In an earlier study, we reported the high throughput screening of a library containing 70,000 compounds, and uncovered a novel class of benzimidazole acrylonitrile-based BoNT/A LC inhibitors. Herein, we present both structure–activity relationships and a proposed mechanism of action for this novel inhibitor chemotype. 相似文献
10.
Heise N Gutierrez AL Mattos KA Jones C Wait R Previato JO Mendonça-Previato L 《Glycobiology》2002,12(7):409-420
Complex glycoinositolphosphoryl ceramides (GIPCs) have been purified from a pathogenic encapsulated wild-type (WT) strain of Cryptococcus neoformans var. neoformans and from an acapsular mutant (Cap67). The structures of the GIPCs were determined by a combination of tandem mass spectrometry, nuclear magnetic resonance spectroscopy, methylation analysis, gas chromatography-mass spectrometry, and chemical degradation. The main GIPC from the WT strain had the structure Manp(alpha1-3)[Xylp(beta1-2)] Manp(alpha1-4)Galp(beta1-6)Manp(alpha1-2)Ins-1-phosphoryl ceramide (GIPC A), whereas the compounds from the acapsular mutant were more heterogeneous in their glycan chains, and variants with Manp(alpha1-6) (GIPC B), Manp(alpha1-6) Manp(alpha1-6) (GIPC C), and Manp(alpha1-2)Manp(alpha1-6)Manp(alpha1-6) (GIPC D) substituents linked to the nonreducing terminal mannose residue found in the WT GIPC A were abundant. The ceramide moieties of C. neoformans GIPCs were composed of a C(18) phytosphingosine long-chain base mainly N-acylated with 2-hydroxy-tetracosanoic acid in the WT GIPC while in the acapsular Cap67 mutant GIPCs, as well as 2-hydroxy-tetracosanoic acid, the unusual 2,3-dihydroxy-tetracosanoic acid was characterized. In addition, structural analysis revealed that the amount of GIPC in the WT cells was fourfold less of that in the acapsular mutant. 相似文献