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991.
The ectomycorrhizal basidiomycete Tricholoma matsutake produces commercially valuable fruit bodies, matsutake, in forests. Here we report a PCR system targeting retroelement integration sites to differentiate among individual Asian isolates of T. matsutake based on their geographical origins, such as Japan, the area of South Korea through North Korea, the northeastern provinces of China, and the area of the southwestern provinces of China through Bhutan. The overall misjudgment rate of the analytical system was approximately 5% based on 95 samples of T. matsutake examined including those from cultures and from commodities. We also provide evidence that T. matsutake isolates grown throughout the Far East, including the northeastern provinces of China, are closely related to each other while distinct from those in the area of the southwestern provinces of China through Bhutan. The method allows us to trace back geographical origins of Asian matsutake, thus contributing to food safety, appropriate tariffs, and proper price setting.  相似文献   
992.
Tetraspanin CD81 is closely homologous in amino acid sequence with CD9. CD9 is well known to be involved in sperm-egg fusion, and CD81 has also been reported to be involved in membrane fusion events. However, the function of CD81 as well as that of CD9 in membrane fusion remains unclear. Here, we report that disruption of the mouse CD81 gene led to a reduction in the fecundity of female mice, and CD81-/- eggs had impaired ability to fuse with sperm. Furthermore, we demonstrated that when CD81-/- eggs were incubated with sperm, some of the sperm that penetrated into the perivitelline space of CD81-/- eggs had not yet undergone the acrosome reaction, indicating that the impaired fusibility of CD81-/- eggs may be in part caused by failure of the acrosome reaction of sperm. In addition, we showed that CD81 was highly expressed in granulosa cells, somatic cells that surround oocytes. Our observations suggest that there is an interaction between sperm and CD81 on somatic cells surrounding eggs before the direct interaction of sperm and eggs. Our results may provide new clues for clarifying the cellular mechanism of the acrosome reaction, which is required for sperm-egg fusion.  相似文献   
993.
We previously developed potent nonviral vectors based on complexation of lipoplexes and pH-sensitive fusogenic liposomes, which achieve efficient transfection through membrane fusion with intracellular acidic compartments such as endosomes. Because transferrin receptor is known to be overexpressed in cancer cells, in this study, we investigated the effect of transferrin as a ligand for transfection of various cancer-derived cell lines mediated by the liposome-lipoplex hybrid complexes. Results showed that these hybrid complexes with transferrin exhibited higher transfection efficiency toward these cells than complexes without transferrin, but the extent of the transferrin-induced enhancement was dependent on the cell line. Conjugation of transferrin increased their transfection activity for HeLa and KB cells, although it only slightly enhanced transfection for HT1080, HepG2, and K562. Transferrin receptors in HT1080, HepG2, and K562 cells were internalized slowly, whereas those in HeLa and KB cells were internalized quickly and actively. These results indicate that transfection mediated by the ligand-attached hybrid complex does not correlate with the amount of transferrin receptor in the cell surface but correlate with the activity of internalization of transferrin receptor into the cells.  相似文献   
994.
We have previously shown that modification with succinylated poly(glycidol) (SucPG) provides stable egg yolk phosphatidylcholine (EYPC) liposomes with pH-sensitive fusogenic property. Toward production of efficient pH-sensitive liposomes, in this study, we newly prepared three carboxylated poly(glycidol) derivatives with varying hydrophobicities by reacting poly(glycidol) with glutaric anhydride, 3-methylglutaric anhydride, and 1,2-cyclohexanedicarboxylic anhydride, respectively, designated as GluPG, MGluPG, and CHexPG. Correlation between side-chain structures of these polymers and their respective abilities to sensitize stable liposomes to pH was investigated. These polymers are soluble in water at neutral pH but became water-insoluble in weakly acidic conditions. The pH at which the polymer precipitated was higher in the order SucPG < GluPG < MGluPG < CHexPG, which is consistent with the number of carbon atoms of these polymers' side chains. Although CHexPG destabilized EYPC liposomes even at neutral pH, attachment of other polymers provided pH-sensitive properties to the liposomes. The liposomes bearing polymers with higher hydrophobicity exhibited more intense responses, such as content release and membrane fusion, at mildly acidic pH and achieved more efficient cytoplasmic delivery of membrane-impermeable dye molecules. As a result, modification with appropriate hydrophobicity, MGluPG, produced highly potent pH-sensitive liposomes, which might be useful for efficient cytoplasmic delivery of bioactive molecules, such as proteins and genes.  相似文献   
995.
996.
A fully automated 2D-HPLC system employing a microbore-ODS column and a narrowbore-enantioselective column has been developed for the simultaneous enantiomer determination of proline, trans-4-hydroxyproline and cis-4-hydroxyproline in mammals. As a first dimension, a monolithic ODS column of 0.53 mm i.d. showed 3-6 times larger theoretical plate numbers than those of particle-packed ODS columns, and the best enantioseparations were obtained by a Chiralpak QN-2-AX column of 1.5 mm i.d. in the second dimension (separation factors: 1.44-1.83). The R.S.D. values for within-day and dayto-day precisions were less than 5.8%, and the lower limits of quantitation for the D-enantiomers were 1 fmol. The present method was successfully applied to the determination of proline and hydroxyproline enantiomers in the serum and collagen-rich skin tissue. Small amounts of D-proline were found both in the serum (1.57 +/- 0.19 nmol/mL) and in the skin (0.093 +/- 0.015 nmol/mg protein), while the amounts of D-hydroxyproline were smaller than the lower limit of quantitation.  相似文献   
997.

Background  

The onset and course of irritable bowel syndrome (IBS) are strongly influenced by psychological factors, and treatment often includes cognitive-behavioral therapy. We conducted a study of the relationships between cognitive appraisal of IBS symptoms and negative mood for the subtypes of IBS.  相似文献   
998.
999.
Modern hard corals (Class Hexacorallia; Order Scleractinia) are widely studied because of their fundamental role in reef building and their superb fossil record extending back to the Triassic. Nevertheless, interpretations of their evolutionary relationships have been in flux for over a decade. Recent analyses undermine the legitimacy of traditional suborders, families and genera, and suggest that a non-skeletal sister clade (Order Corallimorpharia) might be imbedded within the stony corals. However, these studies either sampled a relatively limited array of taxa or assembled trees from heterogeneous data sets. Here we provide a more comprehensive analysis of Scleractinia (127 species, 75 genera, 17 families) and various outgroups, based on two mitochondrial genes (cytochrome oxidase I, cytochrome b), with analyses of nuclear genes (ss-tubulin, ribosomal DNA) of a subset of taxa to test unexpected relationships. Eleven of 16 families were found to be polyphyletic. Strikingly, over one third of all families as conventionally defined contain representatives from the highly divergent "robust" and "complex" clades. However, the recent suggestion that corallimorpharians are true corals that have lost their skeletons was not upheld. Relationships were supported not only by mitochondrial and nuclear genes, but also often by morphological characters which had been ignored or never noted previously. The concordance of molecular characters and more carefully examined morphological characters suggests a future of greater taxonomic stability, as well as the potential to trace the evolutionary history of this ecologically important group using fossils.  相似文献   
1000.
We have successfully developed a catalytic antibody capable of degrading the active site of the urease of Helicobacter pylori and eradicating the bacterial infection in a mouse stomach. This monoclonal antibody UA15 was generated using a designed recombinant protein UreB, which contained the crucial region of the H. pylori urease beta-subunit active site, for immunization. The light chain of this antibody (UA15-L) by itself showed a proteolytic activity to substantially degrade both UreB and the intact urease. Oral administration of UA15-L also significantly reduced the number of H. pylori in a mouse stomach. This is the first example of a monoclonal catalytic antibody capable of functioning in vivo, and such an antibody may have a therapeutic utility in the future.  相似文献   
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