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171.
A. D. da Matta A. M. R. Bernardino G. A. Romeiro M. R. P. de Oliveira M. C. B. V. de Souza V. F. Ferreira 《Nucleosides, nucleotides & nucleic acids》2013,32(4):889-898
Abstract Ribosylation reactions of previously silylated 3-carbethoxy-8-methyl-1,4-dihydro-4-oxoquinoline (6a) and 3-carbethoxy-6-methyl-1,4-dihydro-4-oxoquinoline (6b) with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (7), under Lewis acid catalysis, were studied. The method using hexamethyldisilazane (HMDS)/trimethylchlorosilane (TMCS) mixture for silylation and anhydrous stannic chloride as catalyst for ribosylation failed to give any nucleoside product. On the other hand, the protected nucleoside 3-carbethoxy-6-methyl-1-(2,3,5-tri-O-benzoyl-β-D-ribofuranosyl)-1,4-dihydro-4-oxoquinoline (8b) was obtained in good yields using bis(trimethylsilyl)trifluoroacetamide (BSTFA) containing 1% of TMCS and the same catalyst. Compound 8b was more easily isolated in higher yields with an improvement of the later method by replacing stannic chloride with trimethylsilyl trifluoromethanesulfonate (TMSOTf). De-O-benzoylation of 8b with methanolic sodium hydroxide solution afforded the free riboside 3-carbomethoxy-6-methyl-1-β-D-ribofuranosyl-1,4-dihydro-4-oxoquinoline (9b). The structures of the obtained products were confirmed by their LTV, MS, IR, 1H and 13C-NMR data. 相似文献
172.
María José Buitrago Cristina Elena Canteros Guadalupe Frías De León Ángel González Manoel Marques-Evangelista De Oliveira César O. Muñoz José Antonio Ramirez Adriana Isabel Toranzo Rosely Zancope-Oliveira Manuel Cuenca-Estrella 《Revista iberoamericana de micología》2013,30(4):256-260
BackgroundA multicenter study was conducted. A panel containing DNA from Histoplasma capsulatum, as well as negative and cross-reaction controls, was sent to five different laboratories, members of the MICOMOL network from CYTED Program.AimsThe objective was to assess the accuracy of different PCR protocols to detect H. capsulatum DNA.MethodsSeven different PCR protocols were tested. They were based on PCR techniques and used unicopy and multicopy targets.ResultsMost of these protocols (4/7) were able to detect the smallest amounts of fungal DNA (102 fg/μl). Overall sensitivity was 86% and specificity was 100%. The protocol based on a unicopy target (SCAR220) presented lower sensitivity (43%) but 100% specificity. The real-time protocols tested were highly reproducible, sensitive, and specific. Neither false positives nor cross-reactions were detected in any protocol.ConclusionsAll laboratories were able to amplify H. capsulatum DNA, and real-time PCR seems to be a promising tool to efficiently detect this pathogen in clinical samples. 相似文献
173.
E.G. Santos F.G.P. Costa J.H.V. Silva T.D.D. Martins D.F. Figueiredo‐Lima M. Macari C.J.B. Oliveira P.E.N. Givisiez 《Journal of applied microbiology》2013,114(4):1158-1165
Aims
To evaluate mannan oligosaccharide (MOS) and threonine effects on performance, small intestine morphology and Salmonella spp. counts in Salmonella Enteritidis‐challenged birds.Methods and Results
One‐day‐old chicks (1d) were distributed into five treatments: nonchallenged animals fed basal diet (RB‐0), animals fed basal diet and infected with Salmonella Enteritidis (RB‐I), animals fed high level of threonine and infected (HT‐I), birds fed basal diet with MOS and infected (MOS‐I), birds fed high level of threonine and MOS and infected (HT+MOS‐I). Birds were inoculated at 2d with Salmonella Enteritidis, except RB‐0 birds. Chicks fed higher dietary threonine and MOS showed performance similar to RB‐0 and intestinal morphology recovery at 8 dpi. Salmonella counts and the number of Salmonella‐positive animals were lower in HT+MOS‐I compared with other challenged groups.Conclusion
Mannan oligosaccharides and threonine act synergistically, resulting in improved intestinal environment and recovery after Salmonella inoculation.Significance and Impact of the Study
Nutritional approaches may be useful to prevent Salmonella infection in the first week and putative carcass contamination at slaughter. This is the first report on the possible synergistic effect of mannan oligosaccharides and threonine, and further studies should be performed including performance, microbiota evaluation, composition of intestinal mucins and immune assessment. 相似文献174.
175.
J.C. Souza E.C Vanzela R.A. Ribeiro L.F. Rezende C.A. de Oliveira E.M. Carneiro H.C.F. Oliveira A.C. Boschero 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2013,1831(4):769-775
Aims/hypothesis
Changes in cellular cholesterol level may contribute to beta cell dysfunction. Islets from low density lipoprotein receptor knockout (LDLR−/−) mice have higher cholesterol content and secrete less insulin than wild-type (WT) mice. Here, we investigated the association between cholesterol content, insulin secretion and Ca2 + handling in these islets.Methods
Isolated islets from both LDLR−/− and WT mice were used for measurements of insulin secretion (radioimmunoassay), cholesterol content (fluorimetric assay), cytosolic Ca2 + level (fura-2AM) and SNARE protein expression (VAMP-2, SNAP-25 and syntaxin-1A). Cholesterol was depleted by incubating the islets with increasing concentrations (0–10 mmol/l) of methyl-beta-cyclodextrin (MβCD).Results
The first and second phases of glucose-stimulated insulin secretion (GSIS) were lower in LDLR−/− than in WT islets, paralleled by an impairment of Ca2 + handling in the former. SNAP-25 and VAMP-2, but not syntaxin-1A, were reduced in LDLR−/− compared with WT islets. Removal of excess cholesterol from LDLR−/− islets normalized glucose- and tolbutamide-induced insulin release. Glucose-stimulated Ca2 + handling was also normalized in cholesterol-depleted LDLR−/− islets. Cholesterol removal from WT islets by 0.1 and 1.0 mmol/l MβCD impaired both GSIS and Ca2 + handling. In addition, at 10 mmol/l MβCD WT islet showed a loss of membrane integrity and higher DNA fragmentation.Conclusion
Abnormally high (LDLR−/− islets) or low cholesterol content (WT islets treated with MβCD) alters both GSIS and Ca2 + handling. Normalization of cholesterol improves Ca2 + handling and insulin secretion in LDLR−/− islets. 相似文献176.
Leandro Luiz Borges Fernanda Abreu Santana Isabel Samila Lima Castro Klever Márcio Antunes Arruda Humberto Josué de Oliveira Ramos Maurilio Alves Moreira Everaldo Gonçalves de Barros 《Molecular breeding : new strategies in plant improvement》2013,32(4):933-942
The common bean (Phaseolus vulgaris L.) is the main source of protein and an important source of minerals in several countries around the world. Angular leaf spot, caused by the fungus Pseudocercospora griseola, is one of the major diseases of the common bean. In this work, we used two-dimensional gel electrophoresis and mass spectrometry to analyze alterations in the proteome of common bean leaves challenged with an incompatible race of P. griseola. Twenty-three differentially expressed proteins were detected in leaves of cultivar AND 277 collected at 12, 24 and 48 h after inoculation. The proteins were digested with trypsin and submitted to MALDI-TOF/TOF and MicrOTOF-Q electrospray mass spectrometry. Nineteen of them were identified upon MS/MS fragmentation. Most of these proteins are involved with amino acid metabolism, terpenoid metabolism, phenylpropanoid biosynthesis, antioxidant systems, vitamin and cofactor metabolism, plant–pathogen interaction, carbohydrate metabolism, photosynthesis, or genetic information processing, showing that the interaction in this pathosystem affects different genes from various metabolic pathways and processes. 相似文献
177.
178.
Mara Garcia Tavares Nathalia Teixeira Pietrani Maxwell de Castro Durvale Helder Canto Resende Lucio Antonio de Oliveira Campos 《Genetics and molecular biology》2013,36(1):111-117
Melipona quadrifasciata is a stingless bee widely found throughout the Brazilian territory, with two recognized subspecies, M. quadrifasciata anthidioides, that exhibits interrupted metasomal stripes, and M. quadrifasciata quadrifasciata, with continuous metasomal stripes. This study aimed to estimate the genetic variability of these subspecies. For this purpose, 127 colonies from 15 Brazilian localities were analyzed, using nine species-specific microsatellite primers. At these loci, the number of alleles ranged from three to 15 (mean: 7.2), and the observed heterozygosity (Ho) ranged from 0.03–0.21, while the expected heterozygosity (He) ranged from 0.23–0.47. The genetic distances among populations ranged from 0.03–0.45. The FST multilocus value (0.23) indicated that the populations sampled were structured, and the clustering analysis showed the formation of two subgroups and two more distant populations. The first group contained the subspecies M. quadrifasciata quadrifasciata, and the other, the subspecies M. quadrifasciata anthidioides and the two M. quadrifasciata populations with continuous metasomal stripes from northern Minas Gerais. These results confirmed that the yellow metasomal stripes alone are not a good means for correctly identifying the different subspecies of M. quadrifasciata. 相似文献
179.
Marcelo de Oliveira Barbosa Rubens Rodrigues da Silva Vanessa Carolina de Sena Correia Luana Pereira dos Santos Analía del Valle Garnero Ricardo José Gunski 《Genetics and molecular biology》2013,36(1):70-73
Cytogenetic studies in birds are still scarce compared to other vertebrates. Woodcreepers (Dendrocolaptidae) are part of a highly specialized group within the Suboscines of the New World. They are forest birds exclusive to the Neotropical region and similar to woodpeckers, at a comparable evolutionary stage. This paper describes for the first time the karyotypes of the Olivaceous and the Narrow-billed Woodcreeper using conventional staining with Giemsa and silver nitrate staining of the nucleolar organizer regions (Ag-NORs). Metaphases were obtained by fibular bone marrow culture. The chromosome number of the Olivaceous Woodcreeper was 2n = 82 and of the Narrow-billed Woodcreeper, 2n = 82. Ag-NORs in the largest macrochromosome pair and evidence of a chromosome inversion are described herein for the first time for this group. 相似文献
180.
Karina Motta Melo Ingrid Reale Alves Julio Cesar Pieczarka José Augusto de Oliveira David Cleusa Yoshiko Nagamachi Cesar Koppe Grisolia 《Genetics and molecular biology》2013,36(3):425-429
The frequency of spontaneous micronucleus (MN) formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA) among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN) sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities. 相似文献