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981.
Compositional and transcriptional analyses of reduced zein kernels derived from the opaque2 mutation and RNAi suppression 总被引:1,自引:0,他引:1
982.
Massimo Reverberi Federico Punelli Marzia Scarpari Emanuela Camera Slaven Zjalic Alessandra Ricelli Corrado Fanelli Anna Adele Fabbri 《Applied microbiology and biotechnology》2010,85(6):1935-1946
In Aspergillus nidulans, Aspergillus flavus, and Aspergillus parasiticus, lipoperoxidative signalling is crucial for the regulation of mycotoxin biosynthesis, conidiogenesis, and sclerotia formation.
Resveratrol, which is a lipoxygenase (LOX) and cyclooxygenase inhibitor, downmodulates the biosynthesis of ochratoxin A (OTA)
in Aspergillus ochraceus. In the genome of A. ochraceus, a lox-like sequence (AoloxA; National Center for Biotechnology Information (NCBI) accession number: DQ087531) for a lipoxygenase-like enzyme has been
found, which presents high homology (100 identities, 100 positives %, score 555) with a lox gene of Aspergillus fumigatus (NCBI accession number: XM741370). To study how inhibition of oxylipins formation may affect the A. ochraceus metabolism, we have used a ΔAoloxA strain. This mutant displays a different colony morphology, a delayed conidia formation, and a high sclerotia production.
When compared to the wild type, the ΔAoloxA strain showed a lower basal activity of LOX and diminished levels of 13-hydroperoxylinoleic acid (HPODE) and other oxylipins
derived from linoleic acid. The limited oxylipins formation corresponded to a remarkable inhibition of OTA biosynthesis in
the ΔAoloxA strain. Also, wheat seeds (Triticum durum cv Ciccio) inoculated with the ΔAoloxA mutant did not accumulate 9-HPODE, which is a crucial element in the host defence system. Similarly, the expression of the
pathogenesis-related protein 1 (PR1) gene in wheat seeds was not enhanced. The results obtained contribute to the current knowledge on the role of lipid peroxidation
governed by the AoloxA gene in the morphogenesis, OTA biosynthesis, and in host–pathogen interaction between wheat seeds and A. ochraceus. 相似文献
983.
Aliny Pereira de Lima Flavia de Castro Pereira Cesar Augusto Sam Tiago Vilanova-Costa Alessandra de Santana Braga Barbosa Ribeiro Luiz Alfredo Pavanin Wagner Batista Dos Santos Elisângela de Paula Silveira-Lacerda 《Journal of biosciences》2010,35(3):371-378
Ruthenium(III) complexes are increasingly attracting the interest of researchers due to their promising pharmacological properties.
Recently, we reported that the cis-(dichloro)tetrammineruthenium(III) chloride compound has cytotoxic effects on murine sarcoma 180 (S-180) cells. In an effort
to understand the mechanism responsible for their cytotoxicity, study we investigated the genotoxicity, cell cycle distribution
and induction of apoptosis caused by cis-(dichloro)tetrammineruthenium(III) chloride in S-180 tumour cells. cis-(dichloro)tetrammineruthenium(III) chloride treatment induced significant DNA damage in S-180 cells, as detected by the alkaline
comet assay. In the cell cycle analysis, cis-(dichloro)tetrammineruthenium(III) chloride caused an increase in the number of cells in G1 phase, accompanied by a decrease
in the S and G2 phases after 24 h of treatment. In contrast, the cell cycle distribution of S-180 cells treated with cis-(dichloro)tetrammineruthenium(III) chloride for 48 h showed a concentration-dependent increase in the sub-G1 phase (indicating
apoptosis), with a corresponding decrease in cells in the G1, S and G2 phases. In addition, cis-(dichloro)tetrammineruthenium(III) chloride treatment induced apoptosis in a time-dependent manner, as observed by the increased
numbers of annexin V-positive cells. Taken together, these findings strongly demonstrate that DNA damage, cell cycle changes
and apoptosis may correlate with the cytotoxic effects of cis-(dichloro)tetrammineruthenium(III) chloride on S-180 cells. 相似文献
984.
Maccallini C Patruno A Lannutti F Ammazzalorso A De Filippis B Fantacuzzi M Franceschelli S Giampietro L Masella S Felaco M Re N Amoroso R 《Bioorganic & medicinal chemistry letters》2010,20(22):6495-6499
A series of N-substituted acetamidines and 2-methylimidazole derivatives structurally related to W1400 were synthesized and evaluated as Nitric Oxide Synthase (NOS) inhibitors. Analogs with sterically hindering isopropyl and phenyl substituents on the benzylic carbon connecting the aromatic core of W1400 to the acetamidine nitrogen, showed good inhibitory potency for nNOS (IC(50)=0.2 and 0.3 μM) and selectivity over eNOS (500 and 1166) and to a lesser extent over iNOS (50 and 100). A molecular modeling study allowed to shed light on the effects of the structural modifications on the selectivity of the designed inhibitors toward the different NOS isoforms. 相似文献
985.
Alessandra Nasser Caiafa Fernando Roberto Martins 《Biodiversity and Conservation》2010,19(9):2597-2618
The assessment of species rarity considers local abundance (scarce or abundant population), habitat affinity (stenoecious
or euryecious species), and geographic distribution (stenotopic or eurytopic species). When analyzed together these variables
classify species into eight categories, from common species to those having small populations, unique habitats, and restricted
geographic distribution (form 7), as proposed by Rabinowitz in 1981. Based on these categories, it is possible to calculate
the frequency of the different forms of rarity of the species present in a given site. The Brazilian Atlantic rainforest is
considered a hotspot of the world biodiversity harboring many endemic species, which have restricted geographic distribution.
Our objective was to identify the forms of rarity of tree species and their proportions in the southern portion of the Brazilian
Atlantic rainforest using Rabinowitz’s forms of rarity. All the seven forms of rarity are present in the 846 tree species
we analyzed: 46% eurytopic and 54% stenotopic, 73% euryecious and 27% stenoecious, 76% locally abundant and 24% locally scarce
species. Eurytopic, euryecious locally abundant species accounted for 41.1%, whereas 58.9% were somehow rare: 4.5% eurytopic,
euryecious locally scarce, 0.2% eurytopic, stenoecious locally abundant, 0.1% eurytopic, stenoecious locally scarce, 19.5%
stenotopic, euryecious locally abundant, 8.0% stenotopic, euryecious locally scarce, 15.6% stenotopic, stenoecious locally
abundant, and 11.0% stenotopic, stenoecious locally scarce. Considering that the most restrictive forms of rarity precedes
extinction, the application of Rabinowitz’s system demonstrated that most tree species of the southern Brazilian Atlantic
rainforest are threatened due to their restricted geographic distribution, restriction to a single habitat, reduced local
abundance, or even to a combination of these variables. 相似文献
986.
Paola Barraja Libero Caracausi Patrizia Diana Anna Carbone Alessandra Montalbano Girolamo Cirrincione Paola Brun Giorgio Palù Ignazio Castagliuolo Francesco Dall’Acqua Daniela Vedaldi Alessia Salvador 《Bioorganic & medicinal chemistry》2010,18(13):4830-4843
In the search for new photochemotherapeutic agents, a series of derivatives of the ring system pyrrolo[3,2-h]quinoline—bioisosters of the angular furocoumarin angelicin—were synthesized through a four-step synthetic approach, in reasonable overall yields. Eight of the synthesized derivatives showed a remarkable phototoxicity against a panel of four human tumor cell lines and a great dose UV-A dependence, reaching IC50 values at submicromolar level. The mode of cellular death photoinduced by pyrrolo[3,2-h]quinolines was evaluated through a series of flow cytometric analysis and other tests were performed to clarify their mechanism of action. 相似文献
987.
Laccases are blue multicopper oxidases, catalyzing the oxidation of an array of aromatic substrates concomitantly with the reduction of molecular oxygen to water. These enzymes are implicated in a variety of biological activities. Most of the laccases studied thus far are of fungal origin. The large range of substrates oxidized by laccases has raised interest in using them within different industrial fields, such as pulp delignification, textile dye bleaching, and bioremediation. Laccases secreted from native sources are usually not suitable for large-scale purposes, mainly due to low production yields and high cost of preparation/purification procedures. Heterologous expression may provide higher enzyme yields and may permit to produce laccases with desired properties (such as different substrate specificities, or improved stabilities) for industrial applications. This review surveys researches on heterologous laccase expression focusing on the pivotal role played by recombinant systems towards the development of robust tools for greening modern industry. 相似文献
988.
Mescalchin A Detzer A Weirauch U Hahnel MJ Engel C Sczakiel G 《RNA (New York, N.Y.)》2010,16(12):2529-2536
The Argonaute proteins play essential roles in development and cellular metabolism in many organisms, including plants, flies, worms, and mammals. Whereas in organisms such as Caenorhabditis elegans and Arabidopsis thaliana, creation of Argonaute mutant strains allowed the study of their biological functions, in mammals the application of this approach is limited by its difficulty and in the specific case of Ago2 gene, by the lethality of such mutation. Hence, in human cells, functional studies of Ago proteins relied on phenotypic suppression using small interfering RNA (siRNA) which involves Ago proteins and the RNA interference mechanism. This bears the danger of undesired or unknown interference effects which may lead to misleading results. Thus, alternative methods acting by different regulatory mechanisms would be advantageous in order to exclude unspecific effects. The knockdown may be achieved by using specific antisense oligonucleotides (asONs) which act via an RNase H-dependent mechanism, not thought to interfere with processes in which Agos are involved. Different functional observations in the use of siRNA versus asONs indicate the relevance of this assumption. We developed asONs specific for the four human Agos (hAgos) and compared their activities with those obtained by siRNA. We confirm that hAgo2 is involved in microRNA (miRNA)- and in siRNA-mediated silencing pathways, while the other hAgos play a role only in miRNA-based gene regulation. Using combinations of asONs we found that the simultaneous down-regulation of hAgo1, hAgo2, and hAgo4 led to the strongest decrease in miRNA activity, indicating a main role of these proteins. 相似文献
989.
Tapping RNA silencing pathways for plant biotechnology 总被引:1,自引:0,他引:1
990.
The dynamic interaction of AMBRA1 with the dynein motor complex regulates mammalian autophagy 总被引:1,自引:0,他引:1
Di Bartolomeo S Corazzari M Nazio F Oliverio S Lisi G Antonioli M Pagliarini V Matteoni S Fuoco C Giunta L D'Amelio M Nardacci R Romagnoli A Piacentini M Cecconi F Fimia GM 《The Journal of cell biology》2010,191(1):155-168
Autophagy is an evolutionary conserved catabolic process involved in several physiological and pathological processes such as cancer and neurodegeneration. Autophagy initiation signaling requires both the ULK1 kinase and the BECLIN 1-VPS34 core complex to generate autophagosomes, double-membraned vesicles that transfer cellular contents to lysosomes. In this study, we show that the BECLIN 1-VPS34 complex is tethered to the cytoskeleton through an interaction between the BECLIN 1-interacting protein AMBRA1 and dynein light chains 1/2. When autophagy is induced, ULK1 phosphorylates AMBRA1, releasing the autophagy core complex from dynein. Its subsequent relocalization to the endoplasmic reticulum enables autophagosome nucleation. Therefore, AMBRA1 constitutes a direct regulatory link between ULK1 and BECLIN 1-VPS34, which is required for core complex positioning and activity within the cell. Moreover, our results demonstrate that in addition to a function for microtubules in mediating autophagosome transport, there is a strict and regulatory relationship between cytoskeleton dynamics and autophagosome formation. 相似文献