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121.
To examine plastic willow regrowth response to herbivory, we studied the effect of a boring insect, the swift moth Endoclita excrescens (Hepialidae: Lepidoptera), which does not remove apical meristems, on shoot growth in three willow species—Salix gilgiana, S. eriocarpa, and S. serissaefolia−by direct observations and experiments in the field. We hypothesized that the stem-boring could initiate new lateral bud
activation, and result in secondary shoot regrowth without the removal of the primary apical meristems. There were significantly
more lateral shoots on naturally attacked than unattacked stems, and a significant positive correlation between lateral shoot
density and the number of swift moth tunnels per tree was observed for all three willow species. Artificial boring, and larval
infestation, resulted in an increase in the number of lateral shoots, but did not affect growth of current-year shoots. The
length of lateral shoots differed between species, being significantly longer in S. gilgiana than S. eriocarpa and S. serissaefolia. The results of this study show that compensatory regrowth can result even if herbivory does not remove the apical meristem.
We argue that this type of plant compensatory response is probably widespread, given that the stem-boring is a common feeding
type of insect herbivores. 相似文献
122.
Guinea pigs immunized intracerebrally with avian myeloblastosis virus (AMV) produced antiserum which reacted with intact virus particles in complement fixation. The antigen in question appeared to be located on the surface of the virion and could be distinguished from the type-specific virus envelope and the group-specific internal antigens of chicken leukosis-sarcoma viruses (ChiLSV). The material could be isolated by sequential treatments of AMV with bromelin, Tween 20, and freeze-thawing, and could be purified by differential centrifugation. Electron microscopy analysis indicated the presence of a component resembling the outer membrane of the particle. The antigenic determinant was designated virus membrane antigen (Vm). Further analyses revealed the presence of protein, lipid, and carbohydrate in a material having a molecular weight of about 6,000 as determined by sodium dodecyl sulfate gel electrophoresis. Serological studies suggested that the outer membranes of AMV and other ChiLSV are represented mainly by host cellular material. 相似文献
123.
Yoshiyuki Tohno Setsuko Tohno Takeshi Minnami Yumi Moriwake Masako Utsumi Masa-oki Yamada 《Biological trace element research》1999,69(3):241-248
To elucidate relationships between the decrease of mineral contents in human bones and the accumulation of minerals in the
other human tissues, the contents of phosphorus in human bones, arteries, veins, and cartilages in 27 subjects (17 men and
10 women) were analyzed by inductively coupled plasma-atomic emission spectrometry. These were resected from subjects who
died in the age range 40–98 yr. Calcanei were chosen for analysis of mineral contents in contrast to arteries such as the
femoral, popliteal, and common carotid arteries, veins such as superior and inferior venae cavae, internal jugular, and femoral
veins, and pubic symphyses.
It was found that the content of phosphorus in calcanei was in agreement with that in both the pubic symphysis and the arteries
such as femoral, popliteal, and common carotid arteries, but it was not in agreement with that in the veins such as superior
and inferior venae cavae, internal jugular, and femoral veins. This suggests that phosphorus released from bones is accompanied
by accumulations of phosphorus in the artery and cartilage. 相似文献
124.
We have previously reported that the majority of base substitution mutations of the Escherichia coli supF gene induced by riboflavin mediated photosensitization were G:C to C:G changes, in addition to G:C to T:A changes which were probably caused by 8-hydroxyguanine (oh(8)Gua), in wild type and mutM mutator mutant strains. This implies that lesions other than oh(8)Gua are produced by riboflavin-photosensitization. G:C to C:G base substitutions have been found in the mutations induced by ionizing radiation and reactive oxygen species, as well as spontaneous mutation. To characterize the G:C to C:G mutation, riboflavin- photosensitized plasmid DNA carrying the supF gene was left at room temperature for 5 h in the dark before transfection. The delayed transfection gave a mutational spectrum different from that for immediate transfection. G:C to C:G transversions significantly increased in mutY mutator strain, in which the transversion was not detected in the immediate transfection. Lesions causing G:C to C:G changes increased during 5-h holding after photosensitization and MutY protein presumably takes part in this type of base change mutation. 相似文献
125.
Aika Yamawaki-Ogata Ryotaro Hashizume Xian-Ming Fu Akihiko Usui Yuji Narita 《World journal of stem cells》2014,6(3):278-287
An aortic aneurysm(AA) is a silent but life-threatening disease that involves rupture. It occurs mainly in aging and severe atherosclerotic damage of the aortic wall. Even though surgical intervention is effective to prevent rupture, surgery for the thoracic and thoraco-abdom-inal aorta is an invasive procedure with high mortality and morbidity. Therefore, an alternative strategy for treatment of AA is required. Recently, the molecular pathology of AA has been clarified. AA is caused by an imbalance between the synthesis and degradation of extracellular matrices in the aortic wall. Chronic inflam-mation enhances the degradation of matrices directly and indirectly, making control of the chronic inflamma-tion crucial for aneurysmal development. Meanwhile, mesenchymal stem cells(MSCs) are known to be ob-tained from an adult population and to differentiate into various types of cells. In addition, MSCs have not only the potential anti-inflammatory and immunosuppres-sive properties but also can be recruited into damagedtissue. MSCs have been widely used as a source for celltherapy to treat various diseases involving graft-versus-host disease, stroke, myocardial infarction, and chronicinflammatory disease such as Crohn's disease clinically.Therefore, administration of MSCs might be availableto treat AA using anti-inflammatory and immnosup-pressive properties. This review provides a summary ofseveral studies on "Cell Therapy for Aortic Aneurysm"including our recent data, and we also discuss the pos-sibility of this kind of treatment. 相似文献
126.
Pyridalyl inhibits cellular protein synthesis in insect, but not mammalian, cell lines 总被引:1,自引:0,他引:1
Moriya K Hirakura S Kobayashi J Ozoe Y Saito S Utsumi T 《Archives of insect biochemistry and physiology》2008,69(1):22-31
To gain insight into the mechanism of action and selectivity of the insecticidal activity of pyridalyl, the cytotoxicity of pyridalyl against various insect and mammalian cell lines was characterized by measuring the inhibition of cellular protein synthesis. When the effect of pyridalyl on the cellular protein synthesis in Sf9 cells was evaluated by measuring the incorporation of [(3)H]leucine, rapid and significant inhibition of protein synthesis was observed. However, pyridalyl did not inhibit protein synthesis in a cell-free protein synthesis system, indicating that pyridalyl does not directly inhibit protein synthesis. No obvious cytotoxicity was observed against any of the mammalian cell lines tested. In the case of insect cell lines, remarkable differences in the cytotoxicity of pyridalyl were observed: the highest cytotoxicity (IC50 mM) was found against Sf9 cells derived from Spodoptera frugiperda, whereas no obvious cytotoxicity was observed against BmN4 cells derived from Bombyx mori. Measurements of the insecticidal activity of pyridalyl against Spodoptera litura and B. mori revealed a correlation between the cytotoxicity against cultured cell lines and the insecticidal activity. From these observations, it was concluded that the selective inhibition of cellular protein synthesis by pyridalyl might contribute significantly to the insecticidal activity and the selectivity of this compound. 相似文献
127.
Osamu Sato Satoshi Miura Hiroyuki Maruyama Yanjuan Zhang Dayu Wu Wen Zhang Haitao Xu Ryotaro Matsuda Haoling Sun Jun Tao 《Inorganica chimica acta》2008,361(12-13):3659-3662
The magnetic and photo-magnetic properties of Co dinuclear compounds were studied. The Co compounds, [{Co(tpa)}2(dhbq)](BF4)3 · 2H2O and [{Co(tpa)}2(dhbq)](ClO4)3 · 2H2O, have the structure [(tpa)CoIII-LS–(μ-dhbq)3?–CoIII-LS(tpa)]3? (where LS, H2dhbq, tpa denote low-spin, 2,5-di-hydroxy-1,4-benzoquinone and tris(2-pyridylmethyl)amine, respectively) at room temperature. On heating, these compounds exhibit valence-tautomeric inter-conversion; [(tpa)CoIII-LS–(μ-dhbq)3?–CoIII-LS(tpa)]3? ? [(tpa)CoII-HS–(μ-dhbq)2?–CoIII-LS(tpa)]3? (where HS denotes high-spin). Furthermore, both of these compounds exhibit photo-induced valence tautomerism at low temperature (<60 K). These results show that the electronic structures of these complexes can be controlled by modifying the counter anions. 相似文献
128.
Takaiwa F Sakuta C Choi SK Tada Y Motoyama T Utsumi S 《Plant & cell physiology》2008,49(10):1589-1599
The soybean major storage protein glycinin is encoded by five genes, which are divided into two subfamilies. Expression of A3B4 glycinin in transgenic rice seed reached about 1.5% of total seed protein, even if expressed under the control of strong endosperm-specific promoters. In contrast, expression of A1aB1b glycinin reached about 4% of total seed protein. Co-expression of the two proteins doubled accumulation levels of both A1aB1b and A3B4 glycinins. This increase can be largely accounted for by their aggregation with rice glutelins, self-assembly and inter-glycinin interactions, resulting in the enrichment of globulin and glutelin fractions and a concomitant reduction of the prolamin fraction. Immunoelectron microscopy indicated that the synthesized A1aB1b glycinin was predominantly deposited in protein body-II (PB-II) storage vacuoles, whereas A3B4 glycinin is targeted to both PB-II and endoplasmic reticulum (ER)-derived protein body-I (PB-I) storage structures. Co-expression with A1aB1b facilitated targeting of A3B4 glycinin into PB-II by sequestration with A1aB1b, resulting in an increase in the accumulation of A3B4 glycinin. 相似文献
129.
130.
Sasaki MS Nomura T Ejima Y Utsumi H Endo S Saito I Itoh T Hoshi M 《Radiation research》2008,170(1):101-117
Epidemiological data on the health effects of A-bomb radiation in Hiroshima and Nagasaki provide the framework for setting limits for radiation risk and radiological protection. However, uncertainty remains in the equivalent dose, because it is generally believed that direct derivation of the relative biological effectiveness (RBE) of neutrons from the epidemiological data on the survivors is difficult. To solve this problem, an alternative approach has been taken. The RBE of polyenergetic neutrons was determined for chromosome aberration formation in human lymphocytes irradiated in vitro, compared with published data for tumor induction in experimental animals, and validated using epidemiological data from A-bomb survivors. The RBE of fission neutrons was dependent on dose but was independent of the energy spectrum. The same RBE regimen was observed for lymphocyte chromosome aberrations and tumors in mice and rats. Used as a weighting factor for A-bomb survivors, this RBE system was superior in eliminating the city difference in chromosome aberration frequencies and cancer mortality. The revision of the equivalent dose of A-bomb radiation using DS02 weighted by this RBE system reduces the cancer risk by a factor of 0.7 compared with the current estimates using DS86, with neutrons weighted by a constant RBE of 10. 相似文献