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471.
Expression of adipokines in preimplantation rabbit and mice embryos   总被引:1,自引:1,他引:0  
Recent studies point to a role for adipokines in reproduction. Leptin is involved in embryo metabolism and may participate in embryo-maternal crosstalk. Little is known about potential roles of other adipokines in reproduction. We therefore studied the expression of adiponectin and pathway members during the pre- and periimplantation period in rabbits and mice. Adiponectin protein is localized in glandular epithelium of the rabbit endometrium on day 6 and 8 p.c. and in mouse endometrium on day 3.5 and 5 p.c. Rabbit, but not mice blastocysts express adiponectin mRNA. Adiponectin receptors one and two, adiponectin paralogues and PPARs were found in both species. Both, trophoblast and embryoblast were adiponectin positive. Real time PCR for adipoR1 and adipoR2 in rabbit blastocysts of different gastrulation stages at day 6 p.c. revealed a specific switch in expression: Expression was high in the trophoblast in early stages and in the embryoblast shortly prior to implantation. In conclusion, during the pre- and periimplantation period, members of the adiponectin pathway are expressed in endometrium and blastocysts, with a specific expression pattern in the embryonic disk of the gastrulating rabbit blastocyst, giving support to a role of the adipokine network in blastocyst differentiation and embryo-maternal interactions.  相似文献   
472.
Ubiquitin (Ub)-conjugating enzyme (UBC, E2) receives Ub from Ub-activating enzyme (E1) and transfers it to target proteins, thereby playing a key role in Ub/26S proteasome-dependent proteolysis. UBC has been reported to be involved in tolerating abiotic stress in plants, including drought, salt, osmotic and water stresses. To isolate the genes involved in Cd tolerance, we transformed WT (wild-type) yeast Y800 with a tobacco cDNA expression library and isolated a tobacco cDNA, NtUBC1 (Ub-conjugating enzyme), that enhances cadmium tolerance. When NtUBC1 was over-expressed in tobacco, cadmium tolerance was enhanced, but the Cd level was decreased. Interestingly, 20S proteasome activity was increased and ubiquitinated protein levels were diminished in response to cadmium in NtUBC1 tobacco. By contrast, proteasome activity was decreased and ubiquitinated protein levels were slightly enhanced by Cd treatment in control tobacco, which is sensitive to Cd. Moreover, the oxidative stress level was induced to a lesser extent by Cd in NtUBC1 tobacco compared with control plants, which is ascribed to the higher activity of antioxidant enzymes in NtUBC1 tobacco. In addition, NtUBC1 tobacco displayed a reduced accumulation of Cd compared with the control, likely due to the higher expression of CAX3 (Ca2+/H+ exchanger) and the lower expression of IRT1 (iron-responsive transporter 1) and HMA-A and -B (heavy metal ATPase). In contrast, atubc1 and atubc1atubc2 Arabidopsis exhibited lower Cd tolerance and proteasome activity than WT. In conclusion, NtUBC1 expression promotes cadmium tolerance likely by removing cadmium-damaged proteins via Ub/26S proteasome-dependent proteolysis or the Ub-independent 20S proteasome and by diminishing oxidative stress through the activation of antioxidant enzymes and decreasing Cd accumulation due to higher CAX3 and lower IRT1 and HMA-A/B expression in response to 50 µM Cd challenge for 3 weeks.  相似文献   
473.
Molecular Biology Reports - Nuclear factor erythroid 2-related factor 2 (Nrf2) has a pivotal role in promoting chemoresistance by regulation of antioxidants and detoxification enzymes. Trigonelline...  相似文献   
474.
Gene clustering by latent semantic indexing of MEDLINE abstracts   总被引:1,自引:0,他引:1  
MOTIVATION: A major challenge in the interpretation of high-throughput genomic data is understanding the functional associations between genes. Previously, several approaches have been described to extract gene relationships from various biological databases using term-matching methods. However, more flexible automated methods are needed to identify functional relationships (both explicit and implicit) between genes from the biomedical literature. In this study, we explored the utility of Latent Semantic Indexing (LSI), a vector space model for information retrieval, to automatically identify conceptual gene relationships from titles and abstracts in MEDLINE citations. RESULTS: We found that LSI identified gene-to-gene and keyword-to-gene relationships with high average precision. In addition, LSI identified implicit gene relationships based on word usage patterns in the gene abstract documents. Finally, we demonstrate here that pairwise distances derived from the vector angles of gene abstract documents can be effectively used to functionally group genes by hierarchical clustering. Our results provide proof-of-principle that LSI is a robust automated method to elucidate both known (explicit) and unknown (implicit) gene relationships from the biomedical literature. These features make LSI particularly useful for the analysis of novel associations discovered in genomic experiments. AVAILABILITY: The 50-gene document collection used in this study can be interactively queried at http://shad.cs.utk.edu/sgo/sgo.html.  相似文献   
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Gath HJ  Hell B  Zarrinbal R  Bier J  Raguse JD 《Plastic and reconstructive surgery》2002,109(3):889-93; discussion 894-5
The experiences of seven patients with squamous cell carcinomas of the oral cavity who underwent reconstruction with a bioengineered human dermal replacement (Dermagraft) are examined. The human dermal replacement consists of fibroblasts seeded onto a three-dimensional polymer scaffold to create a living dermal structure. In this setting, the fibroblasts secrete a mixture of growth factors and matrix proteins in physiological concentration that is essential for wound healing and epithelization. The fibroblast tissue remains metabolically active after cryopreservation and can be used as an off-the-shelf tissue to cover medium-sized defects and avoid donor-site morbidity. In the first series of patients treated with this tissue, defect closure was achieved without functional problems, allowing optimal postoperative monitoring for tumor recurrence.  相似文献   
478.
Mutations in either of the two tumor suppressor genes NF1 (neurofibromin) and NF2 (merlin) result in Neurofibromatosis, a condition predisposing individuals to developing a variety of benign and malignant tumors of the central and peripheral nervous systems. Here we report the identification of two distinct NF1-containing complexes, one in the soluble and the other in the particulate fraction of HeLa extract. We show that the soluble NF1 complex delineates a large holo-NF1 complex (2 MDa) encompassing the components of a smaller particulate core-NF1 complex (400 kDa). Purification of the core-NF1 complex followed by mass spectrometric analysis revealed the motor protein, kinesin-1 heavy chain (HsuKHC/KIF5B), as a catalytic subunit of both NF-1-containing complexes. Importantly, although NF1 and NF2 are not in a stable association, NF2 is also a component of a distinct kinesin-1-containing complex. These results point to kinesin-1 as a common denominator between NF1 and NF2.  相似文献   
479.
Caudal nasal deviation   总被引:6,自引:0,他引:6  
Guyuron B  Behmand RA 《Plastic and reconstructive surgery》2003,111(7):2449-57; discussion 2458-9
Caudal nasal deviation, manifested by a "crooked tip," asymmetric nostrils, and a deviated columella, is one of the most challenging deformities encountered in rhinoplasty. This entity is often ignored by rhinoplasty surgeons, on the basis of the assumption that correction of other segments of the deviated nose will improve the caudal nose. Failure to correct this imperfection (or, occasionally, deformity) invariably produces suboptimal results. The nasal structures involved in caudal nasal deviation, namely, the septum, the lower lateral cartilages, and the anterior nasal spine, must be evaluated for identification of the anatomical blocks that have a causative role in caudal nasal deviation. The specific structures with abnormalities related to this deformity are discussed, as are techniques for the correction of the deformities. These techniques significantly augment the surgeon's repertoire of methods for addressing the subtleties of caudal nasal deviation correction and achieving predictable results.  相似文献   
480.
Tumor-targeted drug delivery is an attractive strategy in cancer treatment. We have previously reported a paclitaxel model conjugate using a bombesin receptor-recognizing peptide in which the drug cytotoxicity against H1299 human nonsmall cell lung cancer was enhanced compared to unconjugated taxol. In an effort to expand the development of tumor-recognizing taxanes, paclitaxel (PTX, taxol) was conjugated to the anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibody (MAb) Erbitux (C225) to serve as a model MAb-mediated drug delivery compound. Thus, paclitaxel was derivatized at its 2'-hydroxy function by introduction of a succinate linker, and the carboxyl group of the latter was covalently attached to C225 through amide bond formation. The final product conjugate (PTXC225) was analyzed mass spectrometrically for assessment of the drug-to-antibody ratios. Cytotoxicity screening of the drug-antibody conjugate against A431, UM-SCC-1, and UM-SCC-6 cells indicated an enhancement in cytocidal effect of paclitaxel as compared to those of the free drug, the intact antibody, and a physical mixture of the two (the controls). In A431 cells, the conjugate showed 25.2% +/- 2.2% of apoptosis induction as compared to little or no apoptosis caused by the controls. Biodistribution analysis of the PTXC225 in tumor-implanted nude mice and a tyrosine-kinase assay showed that conjugation of the drug did not interfere with the immunoreactivity of the antibody. The 24-h tumor uptake of C225 and PTXC225 were 11.7% +/- 6.0% and 7.1% +/- 3.6% of the injected dose per gram of tissue (%ID/g), respectively, which were not significantly different. Also, in A431-implanted nude mice, the conjugate and C225 showed tumor growth inhibition effects of 57.2% and 41.2%, respectively, against a saline-treated control, which were not significantly different from each other. This lack of difference in the in vivo antitumor activity of the MAb-delivered drug and free PTX may be due to either a relatively low dose of the antibody-delivered drug (346 microg/kg), or an untimely release of it, or both. The tumor growth inhibition pattern of the conjugate, however, was identical to that of C225, indicating that the attachment of PTX did not affect the antigen-binding and growth inhibitory features of the MAb. These preliminary results demonstrate the potential of tumor-targeted delivery of taxol as a promising strategy in cancer treatment and warrant further work to develop more suitable drug-MAb linkers as well as improved dosage and treatment protocols.  相似文献   
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