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951.
Short interspersed repetitive elements (SINEs) have been shown to be
excellent markers of molecular phylogeny, since the integration of a SINE
at a particular position in a genome can be considered an unambiguous
derived homologous character. In the present study, we isolated a new
family of SINEs from cichlids in Lake Tanganyika, whose speciation and
diversification have been regarded as prime examples of explosive adaptive
radiation. Members of this new SINE family, which we named the AFC family,
are about 320 bp in length, and each has a tRNA- related region in its 5'
region, as do most of the members of SINE families reported to date. A dot
blot hybridization experiment showed that this family is distributed
extensively in the genomes of cichlids in Africa, with estimated copy
numbers of 2 x 10(3)-2 x 10(4) per haploid genome. Our investigations of
the patterns of insertion of members of this family at six orthologous loci
demonstrated clearly that four previously identified tribes, namely, the
Lamprologini, Ectodini, Tropheini, and Perissodini, each form a
monophyletic group. These results provide a basis for the elucidation of
the phylogenetic framework of the cichlid fishes in Lake Tanganyika.
相似文献
952.
953.
Shigeo Uehara Toshisada Nishida Hiroyuki Takasaki Mahale Mountains Wildlife Kohshi Norikoshi Takahiro Tsukahara Ramadhani Nyundo Miya Hamai 《Primates; journal of primatology》1994,35(3):275-281
K Group, originally one of the two major study groups of chimpanzees since 1965 in the Mahale Mountains National Park, western
Tanzania, was almost extinct by 1983: at most seven individuals remained in the group at the beginning of 1983. K Group continued
to exist for more than four years, but in 1987 a male was left alone at the age of 15 after all the other chimpanzees of the
group emigrated or disappeared. Since then he has been observed sporadically for more than five years only within the former
range of K Group, without having any contact with the many resident chimpanzees of the neighboring M Group, the other major
study group. The present observations reconfirm the strong philopatric tendency of adult male chimpanzees. 相似文献
954.
Yubaristrobus is a new genus of the Taxodiaceae based on a permineralized seed cone from the Upper Cretaceous of Hokkaido. The type species,Y. nakajimae sp. nov., is characterized by peltate bract-scale complexes consisting of a completely-fused bract and scale. The bract-scale
complexes are spirally arranged as in most taxodiaceous genera. Their vascular arrangement is specialized and unique in the
Taxodiaceae and suggests a relationship with the Cupressaceae.
Consecutive number from the previous paper (Ohsawa, M. Nishida and H. Nishida, 1992b). 相似文献
955.
Noriko Yamano-Adachi Yuto Nakanishi Wataru Tanaka YuanShan Lai Masahiro Yamazaki Laura Zenner Hirofumi Hata Takeshi Omasa 《Biotechnology and bioengineering》2023,120(3):659-673
Chinese hamster ovary (CHO) cells are major host cells for biopharmaceuticals. During culture, the chromosome number of CHO cells alters spontaneously. Here, we investigated the effects of artificial changes in the chromosome number on productivity. When cell fusion between antibody-producing CHO-K1-derived cells was induced, we observed a wide range of aneuploidy that was not detected in controls. In particular, antibody productivities were high in clone-derived cell populations that retained a diverse chromosome number distribution. We also induced aneuploid cells using 3-aminobenzamide that causes chromosome non-disjunction. After induction of aneuploidy by 3-aminobenzamide, cells with an increased chromosome number were isolated, but cells with a decreased chromosome number could not be isolated. When antibody expression vectors were introduced into these isolated clones, productivity tended to increase in cells with an increased chromosome number. Further analysis was carried out by focusing on clone 5E8 with an average chromosome number of 37. When 5E8 cells were used as host, the productivity of multiple antibodies, including difficult-to-express antibodies, was improved compared with CHO-K1 cells. The copies of exogenous genes integrated into the genome were significantly increased in 5E8 cells. These findings expand the possibilities for host cell selection and contribute to the efficient construction of cell lines for recombinant protein production. 相似文献
956.
Yamada K Kimura S Negishi M Takamatsu J Inagaki M Aihara M Nishida Y Mori K Fukutake K Mimaya J Takata N Shimada K 《Clinical and diagnostic virology》1993,1(4):245-256
Forty-three hemophiliacs with AIDS or ARC received a daily dose of 334 or 500 mg didanosine (2',3'-dideoxyinosine or ddI) orally in 2 divided doses in phase I/II, open-label clinical trial conducted in Japan. Twenty-eight patients completed 6 months of therapy. There was an increase in circulating CD4(+) cells in 19 valuable patients from 91 +/- 25 (mean +/- SE) at entry to 131 +/- 38 at 24 weeks of therapy P = 0.01; Wilcoxon signed rank). Fourteen of 37 patients met the criteria for CD4 rise >/= 50/mm3 rise or >/= 50% increase from entry values) for more than 4 consecutive weeks. Twenty patients were p24 positive at entry. Nine out of the 10 evaluable patients (90%) showed a decline in p24 antigen at weeks 20-24 (P = 0.02). Thirty-five patients had symptoms related to HIV-1 infection at entry. Twenty-seven patients reported improvements in constitutional symptoms during therapy. Nine patients presented with possible drug-related adverse effects, and didanosine was discontinued in 6 patients (one each with edema; abdominal pain with anorexia; hematuria with edema and rash; sense of abdominal distension with anorexia; diarrhea and abdominal pain; and irritability). One patient had a transient increase in serum amylase level to twice the upper limit of normal, but he continued to receive the drug. These data suggest that didanosine was generally well tolerated in hemophiliacs with AIDS or ARC, and its administration correlated with improvement in constitutional symptoms and laboratory findings. The adverse effects of didanosine seen in this population were moderate to mild, and no complications related to hemorrhagic diathesis were observed, although the relative risk of acute pancreatitis in this population (while not seen in the present study to date) requires more study. 相似文献
957.
Koichi Koshimizu Hajime Ohigashi Michael A. Huffman Toshisada Nishida Hiroyuki Takasaki 《International journal of primatology》1993,14(2):345-356
Potential medicinal plants for wild chimpanzees have been studied in order to discover their physiologically active compounds. Tests of the physiological activity of 3 plant species—Vernonia amygdalina, Aspilia mossambicensis, andFicus exasperata—indicate that they contain a variety of active compounds. From one species,V. amygdalina, an antitumor agent and 2 possible antitumor promoters are identified. Furthermore, steroid glucosides were isolated as the bitter substances. These structurally new compounds are expected to exhibit a number of significant physiological activities. The chemical investigation of possible medicinal plants used by chimpanzees should be helpful in recovering naturally occurring compounds of medicinal significance for human use. 相似文献
958.
959.
Requirement for the MAP kinase kinase/MAP kinase cascade in Xenopus oocyte maturation. 总被引:13,自引:4,他引:9
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MAP kinase kinase (MAPKK) has been identified as a protein factor that can induce phosphorylation and activation of inactive MAP kinase in vitro. In this study, we produced an anti-Xenopus MAPKK antibody that can specifically inhibit Xenopus MAPKK activity in vitro. Microinjection of this antibody into immature oocytes prevented progesterone-induced MAP kinase activation. Moreover, progesterone-induced histone H1 kinase activation and germinal vesicle breakdown (GVBD) were inhibited in the oocytes injected previously with this antibody. Furthermore, when a bacterially expressed Mos was introduced into immature oocytes, Mos-induced MAP kinase activation and GVBD were blocked in the oocytes injected with the anti-MAPKK antibody. These results show that MAPKK is responsible for the activation of MAP kinase in vivo and that the MAPKK/MAP kinase cascade plays a pivotal role in the MPF activation during the oocyte maturation process. 相似文献
960.