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991.
Andrés Zurita-Silva Francisco Fuentes Pablo Zamora Sven-Erik Jacobsen Andrés R. Schwember 《Molecular breeding : new strategies in plant improvement》2014,34(1):13-30
Quinoa (Chenopodium quinoa Willd.) originated in the Andean region of South America; this species is associated with exceptional grain nutritional quality and is highly valued for its ability to tolerate abiotic stresses. However, its introduction outside the Andes has yet to take off on a large scale. In the Andes, quinoa has until recently been marginally grown by small-scale Andean farmers, leading to minor interest in the crop from urban consumers and the industry. Quinoa breeding programs were not initiated until the 1960s in the Andes, and elsewhere from the 1970s onwards. New molecular tools available for the existing quinoa breeding programs, which are critically examined in this review, will enable us to tackle the limitations of allotetraploidy and genetic specificities. The recent progress, together with the declaration of “The International Year of the Quinoa” by the Food and Agriculture Organization of the United Nations, anticipates a bright future for this ancient species. 相似文献
992.
Valéria F. Moscardini Pablo C. Gontijo J. P. Michaud Geraldo A. Carvalho 《BioControl》2014,59(5):503-511
The extrafloral nectar (EFN) of sunflower, Helianthus annuus L., is an important summer resource for many insects and represents a potential route of exposure to systemic insecticides applied as seed treatments to cultivated varieties. Among the many parasitoids that utilize sunflower EFN, Lysiphlebus testaceipes (Cresson) (Hymenoptera: Braconidae) is an important generalist parasitoid of cereal aphids in North America. This study evaluated the performance of adult wasps fed EFN of sunflower plants grown from seed treated with chlorantraniliprole and thiamethoxam. Consumption of EFN from treated sunflower seedings caused no lethal effects, but reduced the numbers of greenbug nymphs, Schizaphis graminum Rondani, attacked and parasitized when wasps foraged in Petri dish arenas. Whereas control females self-superparasitized every fourth host, those exposed to chlorantraniliprole did not. Offspring developmental time and adult emergence were unaffected by either treatment, but thiamethoxam greatly reduced the proportion of female offspring. 相似文献
993.
Lisa Klug Pablo Tarazona Clemens Gruber Karlheinz Grillitsch Brigitte Gasser Martin Trötzmüller Harald Köfeler Erich Leitner Ivo Feussner Diethard Mattanovich Friedrich Altmann Günther Daum 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2014,1841(2):215-226
The methylotrophic yeast Pichia pastoris is a popular yeast expression system for the production of heterologous proteins in biotechnology. Interestingly, cell organelles which play an important role in this process have so far been insufficiently investigated. For this reason, we started a systematic approach to isolate and characterize organelles from P. pastoris. In this study, we present a procedure to isolate microsomal membranes at high purity. These samples represent endoplasmic reticulum (ER) fractions which were subjected to molecular analysis of lipids and proteins. Organelle lipidomics included a detailed analysis of glycerophospholipids, fatty acids, sterols and sphingolipids. The microsomal proteome analyzed by mass spectrometry identified typical proteins of the ER known from other cell types, especially Saccharomyces cerevisiae, but also a number of unassigned gene products. The lipidome and proteome analysis of P. pastoris microsomes are prerequisite for a better understanding of functions of this organelle and for modifying this compartment for biotechnological applications. 相似文献
994.
995.
996.
Romina C. Torres Melisa A. Giorgis Cecilia Trillo Luis Volkmann Pablo Demaio Javier Heredia Daniel Renison 《Austral ecology》2014,39(3):346-354
In fire‐prone landscapes, differences in post‐fire regeneration by resprouting between species or sites could be far more important in explaining vegetation physiognomy and composition than seed regeneration. This is the first study exploring the relative contribution of tree resprouts and seeds to post‐fire crown volume in the Chaco Serrano forest of South America. Additionally, we compare the resprouting response among species and quantify post‐fire changes in tree composition among sites. We established 290 permanent plots distributed in three sites affected by wildfires in 2005. For all tree species in all plots we recorded survival of every individual 1 year after the fire; at the plot level, we recorded the above‐ground tree volume before and 3 years after the fire. Resprouting from the base was the main resprouting type. Survival varied between species from 73% to 100% for native species and from 7% to 100% for non‐natives. Before the fire, crown volume was similar in the three sites, and was completely lost after the fire in 92% of the plots. Three years after the fire, between 8% and 58% of crown volume was recovered. The ratio of crown recovery because of resprouts and seedlings was 1562:1. Tree composition exhibited few changes because of the high post‐fire survival of most native species. We conclude that in the semiarid Chaco Serrano ecosystem tree species regenerate mainly by resprouting. This regeneration mode should be taken into account to better understand post‐fire successional pathways of these forests, their management and the restoration of burnt forest areas. 相似文献
997.
Murilo S. Dias Thierry Oberdorff Bernard Hugueny Fabien Leprieur Céline Jézéquel Jean‐François Cornu Sébastien Brosse Gael Grenouillet Pablo A. Tedesco 《Ecology letters》2014,17(9):1130-1140
The relative importance of contemporary and historical processes is central for understanding biodiversity patterns. While several studies show that past conditions can partly explain the current biodiversity patterns, the role of history remains elusive. We reconstructed palaeo‐drainage basins under lower sea level conditions (Last Glacial Maximum) to test whether the historical connectivity between basins left an imprint on the global patterns of freshwater fish biodiversity. After controlling for contemporary and past environmental conditions, we found that palaeo‐connected basins displayed greater species richness but lower levels of endemism and beta diversity than did palaeo‐disconnected basins. Palaeo‐connected basins exhibited shallower distance decay of compositional similarity, suggesting that palaeo‐river connections favoured the exchange of fish species. Finally, we found that a longer period of palaeo‐connection resulted in lower levels of beta diversity. These findings reveal the first unambiguous results of the role played by history in explaining the global contemporary patterns of biodiversity. 相似文献
998.
Tomás?Gutiérrez Valentina?Parra Rodrigo?Troncoso Christian?Pennanen Ariel?Contreras-Ferrat César?Vasquez-Trincado Pablo?E?Morales Camila?Lopez-Crisosto Cristian?Sotomayor-Flores Mario?Chiong Beverly?A?Rothermel Sergio?LavanderoEmail author 《Cell communication and signaling : CCS》2014,12(1):68
Background
Cardiac hypertrophy is characterized by alterations in both cardiac bioenergetics and insulin sensitivity. Insulin promotes glucose uptake by cardiomyocytes and its use as a substrate for glycolysis and mitochondrial oxidation in order to maintain the high cardiac energy demands. Insulin stimulates Ca2+ release from the endoplasmic reticulum, however, how this translates to changes in mitochondrial metabolism in either healthy or hypertrophic cardiomyocytes is not fully understood.Results
In the present study we investigated insulin-dependent mitochondrial Ca2+ signaling in normal and norepinephrine or insulin like growth factor-1-induced hypertrophic cardiomyocytes. Using mitochondrion-selective Ca2+-fluorescent probes we showed that insulin increases mitochondrial Ca2+ levels. This signal was inhibited by the pharmacological blockade of either the inositol 1,4,5-triphosphate receptor or the mitochondrial Ca2+ uniporter, as well as by siRNA-dependent mitochondrial Ca2+ uniporter knockdown. Norepinephrine-stimulated cardiomyocytes showed a significant decrease in endoplasmic reticulum-mitochondrial contacts compared to either control or insulin like growth factor-1-stimulated cells. This resulted in a reduction in mitochondrial Ca2+ uptake, Akt activation, glucose uptake and oxygen consumption in response to insulin. Blocking mitochondrial Ca2+ uptake was sufficient to mimic the effect of norepinephrine-induced cardiomyocyte hypertrophy on insulin signaling.Conclusions
Mitochondrial Ca2+ uptake is a key event in insulin signaling and metabolism in cardiomyocytes.999.
Ari Zeida Carlos M. Guardia Pablo Lichtig Laura L. Perissinotti Lucas A. Defelipe Adrián Turjanski Rafael Radi Madia Trujillo Darío A. Estrin 《Biophysical reviews》2014,6(1):27-46
Thiol redox chemical reactions play a key role in a variety of physiological
processes, mainly due to the presence of low-molecular-weight thiols and cysteine
residues in proteins involved in catalysis and regulation. Specifically, the subtle
sensitivity of thiol reactivity to the environment makes the use of simulation
techniques extremely valuable for obtaining microscopic insights. In this work we
review the application of classical and quantum–mechanical atomistic simulation
tools to the investigation of selected relevant issues in thiol redox biochemistry,
such as investigations on (1) the protonation state of cysteine in protein, (2)
two-electron oxidation of thiols by hydroperoxides, chloramines, and hypochlorous
acid, (3) mechanistic and kinetics aspects of the de novo formation of disulfide
bonds and thiol−disulfide exchange, (4) formation of sulfenamides, (5) formation of
nitrosothiols and transnitrosation reactions, and (6) one-electron oxidation
pathways. 相似文献
1000.
Ying Zhuo Tao Zhang Qi Wang Pablo Cruz‐Morales Buchang Zhang Mei Liu Francisco Barona‐Gómez Lixin Zhang 《Biotechnology journal》2014,9(3):316-325
Natural products are still key sources of current clinical drugs and innovative therapeutic agents. Since wild‐type microorganisms only produce natural products in very small quantities, yields of production strains need to be improved by breaking down the precise genetic and biochemical circuitry. Herein, we use avermectins as an example of production improvement and chemical structure diversification by synthetic biology. Avermectins are macrocyclic lactones produced by Streptomyces avermitilis and are well known and widely used for antiparasitic therapy. Given the importance of this molecule and its derivatives, many efforts and strategies were employed to improve avermectin production and generate new active analogues. This review describes the current status of synthetic strategies successfully applied for developing natural‐product‐producing strains and discusses future prospects for the application of enhanced avermectin production. 相似文献