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81.
Flavonoids extracted from marigold flowers were investigated for their dyeing potential. Patulitrin (1) and patuletin (2) were isolated and their structures established using NMR and HPLC-MS. These compounds were identified as the main flavonoids present in the dyeing bath. Following the dyeing process, it was demonstrated that aglycone 2 bound more strongly to wool fibres than its glucoside 1. Moreover, analysis focused on 1 and 2 dynamics during plant growth revealed that these components were only found in flowers during and after flowering. The influence of growing location was also investigated and it appeared that cultivation under Mediterranean conditions enhanced biosynthesis of 1 and 2 . Finally, several solvents were tested for their potential to extract the flavonoids: the use of a water-ethanol mixture gave a high extraction efficiency and allowed selective extraction of 1 and 2. The implications of these results are discussed in relation to the development of marigold as a potential dyeing plant. 相似文献
82.
GMDD: a database of GMO detection methods 总被引:1,自引:0,他引:1
Wei Dong Litao Yang Kailin Shen Banghyun Kim Gijs A Kleter Hans JP Marvin Rong Guo Wanqi Liang Dabing Zhang 《BMC bioinformatics》2008,9(1):260
Background
Since more than one hundred events of genetically modified organisms (GMOs) have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at global level is needed. 相似文献83.
84.
Background
Comparative genomic data among organisms allow the reconstruction of their phylogenies and evolutionary time scales. Molecular timings have been recently used to suggest that environmental global change have shaped the evolutionary history of diverse terrestrial organisms. Living xenarthrans (armadillos, anteaters and sloths) constitute an ideal model for studying the influence of past environmental changes on species diversification. Indeed, extant xenarthran species are relicts from an evolutionary radiation enhanced by their isolation in South America during the Tertiary era, a period for which major climate variations and tectonic events are relatively well documented. 相似文献85.
JP Herv s J. Martí -Clú a A. Mu oz-Garcí a MC Santa-Cruz 《Biotechnic & histochemistry》2002,77(1):27-35
We have optimised an indirect immunoperoxidase technique demonstrating bromodeoxyuridine (BrdU) incorporation into dividing cells for cerebellar tissue sections of four-day-old rats injected with this marker. This permits confident identification of granule-cell precursors engaged in DNA synthesis in the external granular layer of the developing cerebellum. Preservation of BrdU immunoreactivity is attained using methanol/acetic acid fixation and different pretreatments before immunostaining, while unlabeled nuclei can be recognized clearly after Feulgen or hematoxylin counterstaining. We established conditions to ensure satisfactory BrdU uptake without affecting cell-cycle progression during the postlabeling time period. The dose of BrdU employed provides saturation S-phase labeling from at least 1 h after BrdU delivery. Various kinetic parameters and phase durations have been determined in experiments involving a single injection or cumulative labeling sequences, and the cycle time was calculated based on two models of generative behavior: steady-state and exponential growth. The working hypothesis of steadystate kinetics can be adopted successfully if the existence of neuroblasts with different proliferation rates is taken into account. 相似文献
86.
87.
Phosphorylation and proteasome-dependent degradation of Bcl-2 in mitotic-arrested cells after microtubule damage. 总被引:2,自引:0,他引:2
P Chadebech L Brichese V Baldin S Vidal A Valette 《Biochemical and biophysical research communications》1999,262(3):823-827
Treatment of NIH-OVCAR-3 cells with paclitaxel, a microtubule-stabilizing agent, induces mitotic arrest and apoptosis, but also Bcl-2 phosphorylation. We report here that Bcl-2 phosphorylation precedes Bcl-2 down-regulation and that both events are closely associated with mitotic arrest, but are not sufficient for paclitaxel to trigger apoptosis. Indeed, when paclitaxel-treated cells were induced to exit mitosis in the presence of 2-aminopurine, Bcl-2 phosphorylation and Bcl-2 down-regulation were both inhibited. In contrast, when apoptosis was inhibited by a caspase inhibitor or Bcl-2 over-expression, Bcl-2 phosphorylation and down-regulation still occurred. Furthermore, we show that Bcl-2 is degraded in mitosis by the proteasome-dependent pathway since Bcl-2 down-regulation is inhibited by proteasome inhibitors such as MG132, Lactacystin and LLnL. Taken together these results indicate that mitotic spindle damage results in post-translational modifications of Bcl-2 by phosphorylation and degradation. 相似文献
88.
Castagnone-Sereno P; Semblat JP; Leroy F; Abad P 《Molecular biology and evolution》1998,15(9):1115-1122
A highly abundant satellite DNA comprising 20% of the Meloidogyne fallax
(Nematoda, Tylenchida) genome was cloned and sequenced. The satellite
monomer is 173 bp long and has a high A + T content of 72.3%, with frequent
runs of A's and T's. The sequence variability of the monomers is 2.7%,
mainly due to random distribution of single-point mutations. A search for
evidence of internal repeated subunits in the monomer sequence revealed a
6-bp motif (AAATTT) for which five degenerated repeats, differing by just a
single base pair, could be identified. Pairwise comparison of the M. fallax
satellite with those from the sympatric species Meloidogyne chitwoodi and
Meloidogyne hapla revealed a high sequence similarity (68.39%) with one
satellite DNA subfamily in M. chitwoodi, which indicated an unexpected
close relationship between them. Given the high copy number and the extreme
sequence homogeneity among monomeric units, it may be assumed that the
satellite DNA of M. fallax could have evolved through some recent and
extensive amplification burst in the nematode genome. In this case, its
relatively short life would not yet have allowed the accumulation of random
mutations in independent amplified repeats. Considering the morphological
resemblance between the two species and their ability to produce
interspecific fertile hybrids under controlled conditions, these results
indicate that M. fallax may share a common ancestor with M. chitwoodi, from
which it could have diverged recently. All these data suggest that M.
fallax could be the result of a recent speciation process and show that
Meloidogyne satellite DNAs may be of interest to resolve phylogenetic
relationships among closely related species from this genus.
相似文献
89.
Opiate binding sites were measured in different placental membrane fractions which were characterized by marker enzyme analysis and electron microscopic examination. The distribution pattern of opiate binding sites in the different fractions closely parallels that of placental alkaline phosphatase. These results clearly show thatopiate binding sites are mainly located on the syncitial brush border membrane. The opiate binding sites found on microvillus membrane fraction have the same pharmacological characteristics as the Kappa opiate binding site previously characterized on placental crude membrane fraction. 相似文献
90.
J P Blayac G Ribes G Valette M M Loubatières-Mariani 《Comptes rendus des séances de la Société de biologie et de ses filiales》1981,175(6):821-827
Phenformin (20 mg/kg subcutaneously) as well as propranolol (0.3 mg/kg. i.v.) induced an increase in blood lactate level in the normal anesthetized log; with phenformin a slight decrease in the arterial pH was noted. The combined administration of phenformin (20 mg/kg subcutaneously) and propranolol (0.3 mg/kg. i.v.) induced a more rapid increase in lactate level, a slight reduction of arterial pH and led to the death of the animals in all cases. After a chronic treatment by phenformin (20 mg/kg daily orally during 7 days, the administration of phenformin (20 mg/kg subcutaneously) induced lactic acidosis in 3 out of the 8 animals and death within 150 minutes. In the animals pretreated by phenformin, the combined administration of phenformin (20 mg/kg subcutaneously) and propranolol (0.3 mg/kg i.v.) caused the death of all the animals without the occurrence of lactic acidosis. These results point to the possible toxicity of the propranolol-phenformin combination. 相似文献