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861.
Meritxell Teixidó Ignasi Belda Esther Zurita Xavier Llorà Myriam Fabre Senén Vilaró Fernando Albericio Ernest Giralt 《Journal of peptide science》2005,11(12):789-804
The use of high-throughput methods in drug discovery allows the generation and testing of a large number of compounds, but at the price of providing redundant information. Evolutionary combinatorial chemistry combines the selection and synthesis of biologically active compounds with artificial intelligence optimization methods, such as genetic algorithms (GA). Drug candidates for the treatment of central nervous system (CNS) disorders must overcome the blood-brain barrier (BBB). This paper reports a new genetic algorithm that searches for the optimal physicochemical properties for peptide transport across the blood-brain barrier. A first generation of peptides has been generated and synthesized. Due to the high content of N-methyl amino acids present in most of these peptides, their syntheses were especially challenging due to over-incorporations, deletions and DKP formations. Distinct fragmentation patterns during peptide cleavage have been identified. The first generation of peptides has been studied by evaluation techniques such as immobilized artificial membrane chromatography (IAMC), a cell-based assay, log Poctanol/water calculations, etc. Finally, a second generation has been proposed. 相似文献
862.
B-Lymphocyte Proliferation during Bovine Leukemia VirusInduced Persistent Lymphocytosis Is Enhanced by T-Lymphocyte-Derived Interleukin-2
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Esther S. Trueblood Wendy C. Brown Guy H. Palmer William C. Davis Diana M. Stone Terry F. McElwain 《Journal of virology》1998,72(4):3169-3177
Bovine leukemia virus (BLV)-induced persistent lymphocytosis is characterized by a polyclonal expansion of CD5+ B lymphocytes. To examine the role of the cytokine microenvironment in this virus-induced B-lymphocyte expansion, the expression of interleukin-2 (IL-2), IL-4, IL-10, and gamma interferon (IFN-γ) mRNA, was measured in stimulated peripheral blood mononuclear cells from persistently lymphocytotic BLV-infected cows, nonlymphocytotic BLV-infected cows, and uninfected cows. IL-2 and IL-10 mRNA expression and IL-2 functional activity were significantly increased when peripheral blood mononuclear cells from persistently lymphocytotic cows were stimulated with concanavalin A (ConA). Additionally, during persistent lymphocytosis, peak IL-2 and IL-10 mRNA expression was delayed, and elevated expression was prolonged. To determine the potential biologic importance of increased IL-2 and IL-10 expression, the response of isolated B lymphocytes from persistently lymphocytotic cows to human recombinant cytokines and to cytokine-containing supernatants from isolated T lymphocytes was examined. While recombinant human IL-10 (rhIL-10) did not consistently induce detectable changes, rhIL-2 increased viral protein (p24) and IL-2 receptor expression in isolated B lymphocytes from persistently lymphocytotic cows. Additionally, rhIL-2 and supernatant from ConA-stimulated T lymphocytes enhanced B-lymphocyte proliferation. The stimulatory activity of the T-lymphocyte supernatant could be completely inhibited with a polyclonal anti-rhIL-2 antibody. Finally, polyclonal anti-rhIL-2 antibody, as well as anti-BLV antibody, inhibited spontaneous proliferation of peripheral blood mononuclear cells from persistently lymphocytotic cows, demonstrating that the spontaneous lymphoproliferation characteristic of BLV-induced persistent lymphocytosis is IL-2 dependent and antigen dependent. Collectively, these findings strongly suggest that increased T-lymphocyte expression of IL-2 in BLV-infected cows contributes to development and/or maintenance of persistent B lymphocytosis. 相似文献
863.
W. Courtens Dominique Grossman Nadine Van Roy Ludwine Messiaen Esther Vamos Veronique Toppet Dominique Haumont Catherine Streydio Anna Jauch Joris Robert Vermeesch Frank Speleman 《Human genetics》1998,103(4):497-505
We report on newborn monozygotic twins with a Noonan-like phenotype, and multiple congenital anomalies due to a monocentric
recombinant chromosome 18. The mother carried a paracentric inversion of the long arm of chromosome 18, inv(18)(q21.1q22.3).
Cytogenetic, fluorescent in situ hybridization, comparative genomic hybridization and DNA marker analyses allowed the delineation
of the deleted (18q22.3–qter) and duplicated (18q12.1–q21.1) chromosomal regions in the recombinant chromosome 18, and suggest
that this duplication-deletion chromosome 18 resulted from breakage of a dicentric recombinant chromosome 18 with subsequent
reconstitution of telomeric sequences on the long arm. Marked variability is observed in the phenotypic expression of the
same chromosomal anomaly in these monozygotic twins. The clinical findings of these patients are compared with those reported
in proximal 18q-duplication and distal 18q-deletion patients. The clinical features of both infants are compatible with Noonan
syndrome, suggesting that a locus for this syndrome may be located on the long arm of chromosome 18.
Received: 16 April 1998 / Accepted: 17 June 1998 相似文献
864.
Summary The incidence of virus infections in three lepidopterous insect species was studied from 1965 to 1968 in alfalfa fields in
California. The insects were the alfalfa caterpillar,Colias eurytheme; the beet armyworm,Spodoptera exigua; and the alfalfa looper,Autographa californica. InC. eurytheme, the major virus was a nuclear polyhedrosis virus (NPV); inS. exigua, a granulosis virus (GV) and an NPV; inA. californica, a GV. Virus epizootics did not develop in very high densities ofC. eurytheme. Virus epizootics occurred in low host densities of the three insect species, especially in populations ofA. californica. The virus acted as a density-dependent factor in the regulation of the populations ofS. exigua andA. californica. Temperature, humidity and rainfall had no marked effect on the incidence of virus infections. 相似文献
865.
Inhibition of adenosine 3',5'-monophosphate accumulation in anterior pituitary gland in vitro by growth hormone-release inhibiting hormone 总被引:2,自引:0,他引:2
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