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101.
Hiroshi Shiraishi Hideaki Okamoto Hiromitsu Hara Hiroki Yoshida 《Biochimica et Biophysica Acta (BBA)/General Subjects》2010
Background
Various forms of cell death, such as apoptotic, autophagic and non-lysosomal types, are implicated in normal physiological processes. Apoptotic protease activating factor 1 (Apaf1) is an important component of the intrinsic apoptotic pathway. Deficiency of Apaf1 results in an accumulation of neural progenitor cells (NPCs) in the developing central nervous system and thus, in perinatal lethality. A small percentage of the mutant mice, however, are viable and grow to maturity. The occurrence of such normal mutants implicates alternative cell death pathways during neurogenesis.Methods
NPCs prepared from wild-type or Apaf1-deficient embryos were cultured in growth factor-deprived medium and examined for cell death, caspase activation and morphological alterations. Generation of reactive oxygen species (ROS) and the effects of antioxidants were examined.Results
Wild-type NPCs underwent apoptosis within 24 hours of withdrawal of epidermal growth factor (EGF) or insulin, whereas Apaf1-deficient NPCs underwent cell death but showed no signs of apoptosis. Autophagy was not necessarily accompanied by cell death. Cell death of the Apaf1-deficient NPCs resembled necroptosis—necrosis-like programmed cell death. The necroptosis inhibitor necrostatin-1, however, failed to inhibit the cell death. ROS accumulation was detected in NPCs deprived of growth factors, and an antioxidant partially suppressed the non-apoptotic cell death of Apaf1-deficient NPCs.Conclusions
These data indicate that after withdrawal EGF or insulin withdrawal, the Apaf1-deficient cells underwent non-apoptotic cell death. ROS generation may partially participate in the cell death.General Significance
Non-apoptotic cell death in NPCs may be a compensatory mechanism in the developing CNS of Apaf1-deficient embryos. 相似文献102.
103.
Stress responses in Salix gracilistyla cuttings subjected to repetitive alternate flooding and drought 总被引:2,自引:0,他引:2
To determine the tolerance of Salix gracilistyla to repetitive alternate flooding and drought, we measured leaf stomatal conductance, pre-dawn water potential, osmotic adjustment,
and biomass production under greenhouse conditions. We used a control and nine crossed treatments (F1-D1–F3-D3) in which we
combined 1-, 2-, or 3-week floodings (F) and droughts (D). Leaf stomatal conductance was lowest in 3 weeks of flooding or
drought when the preceding event (flood or drought) was also of a 3-week duration. Leaf pre-dawn water potential was reduced
in 3 weeks of drought when preceded by 2 or 3 weeks of flooding. Cuttings had slight osmotic adjustments in repetitions of
long floodings and droughts. During longer durations of drought in crossed experiments, plants had low root and shoot mass,
few hypertrophic lenticels, and reduced leaf mass; when flooding duration increased in crossed experiments, root mass was
reduced, there were more hypertrophic lenticels, and the leaf area was reduced. Cuttings achieved stress tolerance by inhibition
of transpiration, osmotic adjustment, reduction of transpiration area, and development of hypertrophic lenticels. Stress tolerance
was weak when repetitive 2- or 3-week floodings were combined with 3-week droughts. The duration of flooding and drought periods
under which S. gracilistyla achieves stress tolerance may be critical in determining distributions along riverbanks. 相似文献
104.
Pyrrole derivatives as potent inhibitors of lymphocyte-specific kinase: Structure,synthesis, and SAR
Tetsuo Takayama Hiroki Umemiya Hideaki Amada Tetsuya Yabuuchi Fumiyasu Shiozawa Hironori Katakai Akiko Takaoka Akie Yamaguchi Mayumi Endo Masakazu Sato 《Bioorganic & medicinal chemistry letters》2010,20(1):108-111
We have described the synthesis, enzyme inhibitory activity, structure–activity relationships, and proposed binding mode of a novel series of pyrrole derivatives as lymphocyte-specific kinase (Lck) inhibitors. The most potent analogs exhibited good enzyme inhibitory activity (IC50s <10 nM) for Lck kinase inhibition. 相似文献
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108.
Yukihiro Kabeya Hiromitsu Nakanishi Kenji Suzuki Takanari Ichikawa Youichi Kondou Minami Matsui Shin-ya Miyagishima 《BMC plant biology》2010,10(1):57
Background
Reminiscent of their free-living cyanobacterial ancestor, chloroplasts proliferate by division coupled with the partition of nucleoids (DNA-protein complexes). Division of the chloroplast envelope membrane is performed by constriction of the ring structures at the division site. During division, nucleoids also change their shape and are distributed essentially equally to the daughter chloroplasts. Although several components of the envelope division machinery have been identified and characterized, little is known about the molecular components/mechanisms underlying the change of the nucleoid structure. 相似文献109.
Takezawa T Takeuchi T Nitani A Takayama Y Kino-Oka M Taya M Enosawa S 《Journal of biotechnology》2007,131(1):76-83
We previously succeeded in converting a soft and turbid disk of type-I collagen gel into a strong and transparent vitrigel membrane utilizing a concept for the vitrification of heat-denatured proteins and have demonstrated its protein-permeability and advantage as a scaffold for reconstructing crosstalk models between two different cell types. In this study, we observed the nano-structure of the type-I collagen vitrigel membrane and verified its utility for paracrine assays in vitro and drug delivery systems in vivo. Scanning electron microscopic observation revealed that the vitrigel membrane was a dense network architecture of typical type-I collagen fibrils. In the crosstalk model between PC-12 pheochromocytoma cells and L929 fibroblasts, nerve growth factor (NGF) secreted from L929 cells passed through the collagen vitrigel membrane and induced the neurite outgrowth of PC-12 cells by its paracrine effect. Also, the collagen vitrigel membrane containing vascular endothelial growth factor (VEGF) showed sustained-release of VEGF in vitro and its subcutaneous transplantation into a rat resulted in remarkable angiogenesis. These data suggest that the collagen vitrigel membrane is useful for paracrine assays in vitro and drug delivery systems in vivo. 相似文献
110.
The adenovirus vector is very attractive tool not only for the gene therapy but also for the basic sciences. However, because a construction method of this vector had been complex, only limited scientists had constructed and enjoyed the benefits. Recently, various methods were developed and the researchers came to be able to choose an efficient method, which is the COS-TPC method, or a concise procedure, which is the intact-genome transfection method (in vitro ligation method). Here we described not only these methods but also new method to construct the various Ads simultaneously using the recombinase-mediated cassette exchange (RMCE) by the site-specific recombinase. And also we want to refer the possibility to the worth of the vector, especially the vector of the expression-switch. 相似文献