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91.
Cámara Y Duval C Sibille B Villarroya F 《The international journal of biochemistry & cell biology》2007,39(1):146-160
While the acquisition of apoptosis resistance is part of the differentiation program of skeletal muscle cells, differentiated muscle cells can undergo apoptosis in response to physiological or pathological stimuli. The generation of reactive oxygen species by mitochondria plays a major role in the control of apoptosis in many cell types. Indeed their involvement in controlling apoptosis in differentiated muscle cells, or in generating resistance to apoptosis remains unknown. Moreover, differentiated muscle cells specifically express the uncoupling protein-3, a mitochondrial protein potentially involved in controlling reactive oxygen species production. To study the role of mitochondrial reactive oxygen species in the control of apoptosis in skeletal muscle cells, L6E9 myoblasts and myotubes were exposed to staurosporine, an inducer of apoptosis via mitochondrial pathways. Staurosporine activated apoptotic pathways (i.e. caspase-3 and caspase-9) increasing reactive oxygen species in myoblasts and, to a minor extent, in myotubes. However, the increase in reactive oxygen species was not needed to induce apoptosis nor was it involved in the differential sensitization of myoblasts and myotubes to apoptosis. Moreover, expression of uncoupling protein-3 in myotubes did not affect reactive oxygen species production, although it produced a slight sensitization for staurosporine-induced apoptosis. Results indicate that apoptotic activation in skeletal muscle cells mainly involves reactive oxygen species-independent mechanisms and that mitochondrial uncoupling protein-3 is not protective either for reactive oxygen species production or for apoptotic activation in muscle cells. 相似文献
92.
93.
Systematics and biogeography of Pleurobranchus Cuvier, 1804 sea slugs (Heterobranchus: Nudipleura: Pleurobranchidae). Addendum 下载免费PDF全文
94.
Godinho R Llaneza L Blanco JC Lopes S Álvares F García EJ Palacios V Cortés Y Talegón J Ferrand N 《Molecular ecology》2011,20(24):5154-5166
Hybridization between wild species and their domestic counterparts may represent a major threat to natural populations. However, high genetic similarity between the hybridizing taxa makes the detection of hybrids a difficult task and may hinder attempts to assess the impact of hybridization in conservation biology. In this work, we used a combination of 42 autosomal microsatellites together with Y-chromosome microsatellite-defined haplotypes and mtDNA sequences to investigate the occurrence and dynamics of wolf-dog hybridization in the Iberian Peninsula. To do this, we applied a variety of Bayesian analyses and a parallel set of simulation studies to evaluate (i) the differences between Iberian wolves and dogs, (ii) the frequency and geographical distribution of hybridization and (iii) the directionality of hybridization. First, we show that Iberian wolves and dogs form two well-differentiated genetic entities, suggesting that introgressive hybridization is not a widespread phenomenon shaping both gene pools. Second, we found evidence for the existence of hybridization that is apparently restricted to more peripheral and recently expanded wolf populations. Third, we describe compelling evidence suggesting that the dynamics of hybridization in wolf populations is mediated by crosses between male dogs and female wolves. More importantly, the observation of a population showing the occurrence of a continuum of hybrid classes forming mixed packs may indicate that we have underestimated hybridization. If future studies confirm this pattern, then an intriguing avenue of research is to investigate how introgression from free-ranging domestic dogs is enabling wolf populations to adapt to the highly humanized habitats of southern Europe while still maintaining their genetic differentiation. 相似文献
95.
María-Estrella Legaz María Blanch Dolores Pi?ón Rocío Santiago Blanca Fontaniella Yolanda Blanco María-Teresa Solas Carlos Vicente 《Plant signaling & behavior》2011,6(8):1132-1139
Visual symptoms of leaf scald necrosis in sugarcane (Saccharum officinarum) leaves develop in parallel to the accumulation of a fibrous material invading exocellular spaces and both xylem and phloem. These fibers are produced and secreted by the plant-associated bacterium Xanthomonas albilineans. Electron microscopy and specific staining methods for polysaccharides reveal the polysaccharidic nature of this material. These polysaccharides are not present in healthy leaves or in those from diseased plants without visual symptoms of leaf scald. Bacteria in several leaf tissues have been detected by immunogold labeling. The bacterial polysaccharide is not produced in axenic culture but it is actively synthesized when the microbes invade the host plant. This finding may be due to the production of plant glycoproteins, after bacteria infection which inhibit microbial proteases. In summary, our data are consistent with the existence of a positive feedback loop in which plant-produced glycoproteins act as a cell-to-bacteria signal that promotes xanthan production, by protecting some enzymes of xanthan biosynthesis against from bacterial proteolytic degradation.Key words: leaf scald, infectivity, Saccharum officinarum (L.) cv. mayarí 55-14, sugarcane glycoproteins, xanthan-like polysaccharide, Xanthomonas albilineans 相似文献
96.
Lorente M Torres S Salazar M Carracedo A Hernández-Tiedra S Rodríguez-Fornés F García-Taboada E Meléndez B Mollejo M Campos-Martín Y Barcia JA Guzmán M Velasco G 《Autophagy》2011,7(9):1071-1073
Δ?-tetrahydrocannabinol (THC), the main active component of marijuana, promotes cancer cell death via autophagy stimulation. We find that activation of the tyrosine kinase receptor ALK by its ligand midkine interferes with the signaling mechanism by which THC promotes autophagy-mediated glioma cell death. 相似文献
97.
Mariem Bouhadida Mar��a ��ngeles Moreno Mar��a Jos�� Gonzalo Jos�� Manuel Alonso Yolanda Gogorcena 《Tree Genetics & Genomes》2011,7(2):257-270
A set of 94 peach cultivars including Spanish native peach and foreign commercial cultivars were analyzed using 15 SSR markers,
selected for their high level of polymorphism. The number of alleles obtained varied from two to 11 with an average of 6.73
giving 185 different genotypes. All the cultivars showed a unique genetic profile, each one using different genotypic combination
of all loci. BPPCT001 was the most informative locus showing also the highest discrimination power. Only six loci allowed
the unambiguous separation of all the Spanish native cultivars studied, and the genotypic combination of only eight loci permitted
the total differentiation of the 94 peach cultivars analyzed. The six selected loci (BPPCT001, BPPCT006, BPPCT008, PS9f8,
UDP98-022, and UDP98-412) seem to be very useful for future Spanish peach identification works, and they will help to establish
a molecular data base for native peach cultivars. UPGMA analysis was performed from the genetic distance matrix, and allowed
the arrangement of all genotypes according to their genetic diversity. The genetic diversity among cultivars, observed in
this work, led to their separation according to their regional origin, their morphological characteristics, and especially
according to their fruit traits. Analysis of molecular variance was performed for seven populations from different regions
of Spain and USA to examine the distribution of genetic variation of the studied accessions, showing that the major variation
occurred within populations in each geographic site. The results reveal the existence of two diversity regions in Spain for
peach germplasm. 相似文献
98.
Knockout rats generated by embryo microinjection of TALENs 总被引:3,自引:0,他引:3
Tesson L Usal C Ménoret S Leung E Niles BJ Remy S Santiago Y Vincent AI Meng X Zhang L Gregory PD Anegon I Cost GJ 《Nature biotechnology》2011,29(8):695-696
99.
100.
Chang KH Multani PS Sun KH Vincent F de Pablo Y Ghosh S Gupta R Lee HP Lee HG Smith MA Shah K 《Molecular biology of the cell》2011,22(9):1452-1462
Nuclear fragmentation is a common feature in many neurodegenerative diseases, including Alzheimer's disease (AD). In this study, we show that nuclear lamina dispersion is an early and irreversible trigger for cell death initiated by deregulated Cdk5, rather than a consequence of apoptosis. Cyclin-dependent kinase 5 (Cdk5) activity is significantly increased in AD and contributes to all three hallmarks: neurotoxic amyloid-β (Aβ), neurofibrillary tangles (NFT), and extensive cell death. Using Aβ and glutamate as the neurotoxic stimuli, we show that deregulated Cdk5 induces nuclear lamina dispersion by direct phosphorylation of lamin A and lamin B1 in neuronal cells and primary cortical neurons. Phosphorylation-resistant mutants of lamins confer resistance to nuclear dispersion and cell death on neurotoxic stimulation, highlighting this as a major mechanism for neuronal death. Rapid alteration of lamin localization pattern and nuclear membrane change are further supported by in vivo data using an AD mouse model. After p25 induction, the pattern of lamin localization was significantly altered, preceding neuronal death, suggesting that it is an early pathological event in p25-inducible transgenic mice. Importantly, lamin dispersion is coupled with Cdk5 nuclear localization, which is highly neurotoxic. Inhibition of nuclear dispersion rescues neuronal cells from cell death, underscoring the significance of this event to Cdk5-mediated neurotoxicity. 相似文献