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121.
The genus Laranda has six described species and is confined to South and Southeast of Brazil. We describe a new species and discuss the biology and distribution of the genus. The new species can be distinguished from its known congeners by the following characteristics: absence of yellow spots on pronotum and base of posterior tibiae; female copulatory papilla: sclerotization in dorsal view forming opposing acute angles, apical lobes narrow and small; male genitalia: pseudepiphallic median process short and wide; pseudepiphallic paramere with apex incurved and ectophallic fold surpassing apex of the parameres. The genus is distributed within the Atlantic Forest biome; the new species is found on tree trunks, as well as on forest leaf litter. 相似文献
122.
Raspaglio G Filippetti F Prislei S Penci R De Maria I Cicchillitti L Mozzetti S Scambia G Ferlini C 《Gene》2008,409(1-2):100-108
Class III beta-tubulin (TUBB3) overexpression represents a major mechanism of drug resistance to microtubule interacting agents such as taxanes and Vinca alkaloids. Here, we tested hypoxia as a possible inducer of TUBB3. The effects of hypoxia on TUBB3 expression were monitored at mRNA and protein level in A2780, in its paclitaxel-resistant counterpart (TC1) and in HeLa cells. Hypoxia was a strong inducer of TUBB3 in A2780, but not in TC1 and HeLa cells. In A2780 HIF-1alpha was knocked down using RNA interference and TUBB3 expression was assessed in normoxia and hypoxia. The silencing abolished the hypoxia-dependent increase of TUBB3, thereby demonstrating that HIF-1alpha mediates TUBB3 induction in hypoxia. To investigate this phenomenon, the 5' flanking region of human TUBB3 was cloned upstream GFP as a reporter. This region contained the promoter gene, but activity of the reporter was unaffected by hypoxia. Thus, we looked at the 3' flanking region and, at +168 nucleotides from the stop codon, an HIF-1alpha binding site was proven to be active in hypoxia, using a construct in which the site was cloned downstream GFP as reporter gene. Deletion of the site in the construct abolished GFP enhancement upon hypoxia. Chromatin immunoprecipitation revealed the engagement by HIF-1alpha of this site in hypoxia. Methylation analysis of this 3' enhancer showed that it was free of methylation in 70% of cells in A2780, while in less than 16% in both TC1 and HeLa cells, thereby suggesting that TUBB3 increase upon hypoxia is abolished through methylation of the 3' enhancer. 相似文献
123.
Ursino M Cuppini C Magosso E Serino A di Pellegrino G 《Journal of computational neuroscience》2009,26(1):55-73
Neurons in the superior colliculus (SC) are known to integrate stimuli of different modalities (e.g., visual and auditory)
following specific properties. In this work, we present a mathematical model of the integrative response of SC neurons, in
order to suggest a possible physiological mechanism underlying multisensory integration in SC. The model includes three distinct
neural areas: two unimodal areas (auditory and visual) are devoted to a topological representation of external stimuli, and
communicate via synaptic connections with a third downstream area (in the SC) responsible for multisensory integration. The
present simulations show that the model, with a single set of parameters, can mimic various responses to different combinations
of external stimuli including the inverse effectiveness, both in terms of multisensory enhancement and contrast, the existence
of within- and cross-modality suppression between spatially disparate stimuli, a reduction of network settling time in response
to cross-modal stimuli compared with individual stimuli. The model suggests that non-linearities in neural responses and synaptic
(excitatory and inhibitory) connections can explain several aspects of multisensory integration. 相似文献
124.
Antonella Pepe Liang Sun Ilaria Zanardi Xinyuan Wu Cristiano Ferlini Gabriele Fontana Ezio Bombardelli Iwao Ojima 《Bioorganic & medicinal chemistry letters》2009,19(12):3300-3304
Novel C-seco-taxoids were synthesized from 10-deacetylbaccatin III and their potencies evaluated against drug-sensitive and drug-resistant cancer cell lines. The drug-resistant cell lines include ovarian cancer cell lines resistant to cisplatin, topotecan, adriamycin and paclitaxel overexpressing class III β-tubulin, A2780TC1 and A2780TC3. The last two cell lines were selected through chronic exposure of A2780wt to paclitaxel and Pgp blocker cyclosporine. All novel C-seco-taxoids exhibited remarkable potency against A2780TC1 and A2780TC3 cell lines, and no cross resistance to cisplatin- and topotecan-resistant cell lines, A2780CIS and A2780TOP. Four of those C-seco-taxoids exhibit much higher activities than IDN5390 against paclitaxel-resistant cell lines, A2780ADR, A2780TC1 and A2780TC3. SB-CST-10202 possesses the best all-round high potencies across different drug-resistant cell lines. Molecular modeling studies, including molecular dynamics simulations, on the drug-protein complexes of class I and III β-tubulins were performed to identify possible cause of the remarkable potency of these C-seco-taxoids against paclitaxel-resistant cell lines overexpressing class III β-tubulin. 相似文献
125.
Di Michele M Della Corte A Cicchillitti L Del Boccio P Urbani A Ferlini C Scambia G Donati MB Rotilio D 《Biochimica et biophysica acta》2009,1794(2):225-236
Ovarian cancer is the leading cause of gynaecological cancer mortality. Paclitaxel is used in the first line treatment of ovarian cancer, but acquired resistance represents the most important clinical problem and a major obstacle to a successful therapy. Several mechanisms have been implicated in paclitaxel resistance, however this process has not yet been fully explained. To better understand molecular resistance mechanisms, a comparative proteomic approach was undertaken on the human epithelial ovarian cancer cell lines A2780 (paclitaxel sensitive), A2780TC1 and OVCAR3 (acquired and inherently resistant). Proteins associated with chemoresistance process were identified by DIGE coupled with mass spectrometry (MALDI-TOF and LC-MS/MS). Out of the 172 differentially expressed proteins in pairwise comparisons among the three cell lines, 151 were identified and grouped into ten main functional classes. Most of the proteins were related to the category of stress response (24%), metabolism (22%), protein biosynthesis (15%) and cell cycle and apoptosis (11%), suggesting that alterations of those processes might be involved in paclitaxel resistance mechanisms. This is the first direct proteomic comparison of paclitaxel sensitive and resistant ovarian cancer cells and may be useful for further studies of resistance mechanisms and screening of resistance biomarkers for the development of tailored therapeutic strategies. 相似文献
126.
127.
Elena Marangon Cristiano Falcioni Carla Manzotti Gabriele Fontana Maurizio D’Incalci Massimo Zucchetti 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2009,877(32):4147-4153
Two LC-ESI–MS and CID-MS/MS methods were developed and validated for pharmacokinetic studies of the novel oral taxane derivatives IDN 5738 and IDN 5839, used for preclinical evaluation in mice. The analysis requires 100 μL of plasma sample, involves the addition of an internal standard and protein precipitation with 0.1% HCOOH in acetonitrile. The HPLC separation was obtained on Sunfire C18 column and Selected Reaction Monitoring technique was used to quantify the taxanes. The recoveries were more than 90%; the methods were linear over the validated concentrations range of 25–1500 ng/mL for IDN 5738 and 25–5000 ng/mL for IDN 5839 and had a limit of detection of 0.14 and 0.25 ng/mL, respectively. The inter-day coefficient of variation (CV%) of the calibration standards ranged between 1.3 and 7.2% for IDN 5738 and between 0.0 and 9.0% for IDN 5839 and the mean accuracy was in the range 85.3–112.0% for IDN 5738 and between 80.0 and 111.0% for IDN 5839. Moreover, analysing quality control plasma samples on three different days, the methods resulted precise and accurate showing intra- and inter-day CV within 12% for both analytes, and accuracy of 92.0–113.3% and 85.9–105.7% for IDN 5738 and IDN 5839, respectively. With these methods, we studied for the first time, the pharmacokinetics of the two taxanes showing for both, good oral bioavailability (>50%). 相似文献
128.
Katia C. S. Figueiredo Helen C. Ferraz Cristiano P. Borges Tito L. M. Alves 《The protein journal》2009,28(5):224-232
The structural stability of metmyoglobin in organic solvents and cosolvents was investigated aiming the choice of a suitable
medium to perform its dissolution with maintenance of the native folding. The spectroscopic behavior of metmyoglobin solution
in UV–Visible and circular dichroism was used to evaluate the solubility and the secondary structure. The results were dependable
of the chemical structure of the organic compounds, their polarity and content, in the case of cosolvents. Protic solvents
showed better ability than the aprotic ones for the biomolecule dissolution, since they are able to establish hydrogen bonds.
Solvents with high polarity usually damage the secondary structure of the protein. Myoglobin was dissolved in pure methanol,
ethylene glycol and glycerol. The secondary structure was retained in some extent. The controlled addition of sodium dodecyl
sulfate to myoglobin aqueous solution changed the surface moiety of the protein. The complex was extracted to hexane with
efficiency of 77%. 相似文献
129.
130.
Devendra Bansal Fabien Herbert Pharath Lim Prakash Deshpande Christophe Bécavin Vincent Guiyedi Ilaria de Maria Jean Claude Rousselle Abdelkader Namane Rajendra Jain Pierre-André Cazenave Gyan Chandra Mishra Cristiano Ferlini Constantin Fesel Arndt Benecke Sylviane Pied 《PloS one》2009,4(12)