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981.
982.
983.
Qiang Gao Yanfang Shang Wei Huang Chengshu Wang 《Applied and environmental microbiology》2013,79(24):7646-7653
Enzymes involved in the triacylglycerol (TAG) biosynthesis have been well studied in the model organisms of yeasts and animals. Among these, the isoforms of glycerol-3-phosphate acyltransferase (GPAT) redundantly catalyze the first and rate-limiting step in glycerolipid synthesis. Here, we report the functions of mrGAT, a GPAT ortholog, in an insect-pathogenic fungus, Metarhizium robertsii. Unlike in yeasts and animals, a single copy of the mrGAT gene is present in the fungal genome and the gene deletion mutant is viable. Compared to the wild type and the gene-rescued mutant, the ΔmrGAT mutant demonstrated reduced abilities to produce conidia and synthesize TAG, glycerol, and total lipids. More importantly, we found that mrGAT is localized to the endoplasmic reticulum and directly linked to the formation of lipid droplets (LDs) in fungal cells. Insect bioassay results showed that mrGAT is required for full fungal virulence by aiding fungal penetration of host cuticles. Data from this study not only advance our understanding of GPAT functions in fungi but also suggest that filamentous fungi such as M. robertsii can serve as a good model to elucidate the role of the glycerol phosphate pathway in fungal physiology, particularly to determine the mechanistic connection of GPAT to LD formation. 相似文献
984.
Gui-dong Liu Xiang Zhai Ling-Ling Wang Ben-xin Wang Qi Lin Xiong-jun Shang 《Plasmonics (Norwell, Mass.)》2016,11(2):381-387
We present the strength modulation and frequency tuning of Fano resonance by employing a graphene nanodimer formed by two coplanar perpendicular nanostrips with different dimensions. The Fano resonance is induced by destructive interference between the bright dipole mode of a short nanostrip and the dark quadrupole mode of a long nanostrip. The strength, line width, and resonance frequency of the Fano resonance can be actively modulated by changing the spatial separation of those two graphene nanostrips and the Fermi energy of the graphene nanodimer, respectively, without re-fabricating the nanostructures. The tuning of the strength and resonance frequency can be attributed to the coupling strength and optical properties of graphene, respectively. Importantly, a figure of merit value as high as 39 is achieved in the proposed nanostructures. Our results may provide potential applications in optical switching and bio-chemical sensing. 相似文献
985.
986.
SUMO (small ubiquitin-like modifier) plays important roles in diverse processes by posttranslationally modifying many proteins.
Here we report the resonance assignment of the truncated SUMO from Trypanosoma brucei. 相似文献
987.
Bioassay‐guided isolation of a fungal strain Nigrospora sp. MA75, an endophytic fungus obtained from the marine semi‐mangrove plant Pongamia pinnata, which was fermented on three different culture media, resulted in the isolation and identification of seven known compounds, 2, 3 , and 5 – 9 , from a medium containing 3.5% NaCl, while a new compound, 2,3‐didehydro‐19α‐hydroxy‐14‐epicochlioquinone B ( 10 ) was obtained from the medium containing 3.5% NaI. In addition, two new griseofulvin derivatives, 6‐O‐desmethyldechlorogriseofulvin ( 1 ) and 6′‐hydroxygriseofulvin ( 4 ), were isolated and identified from the rice solid medium. Dechlorogriseofulvin ( 2 ) and griseofulvin ( 3 ) were the major components in fermentation extracts of all these culture media, while compounds 1 and 4, 5 and 6 , and 10 were only present in the extract of respective culture medium. The structures of these compounds were elucidated by detailed spectroscopic analysis, and the absolute configuration of 1 was determined by CD measurement. Compounds 9 and 10 exhibited antibacterial activities toward five tested bacterial strains, while compounds 5, 6 , and 8 selectively inhibited MRSA, E. coli, and S. epidermidis, and compound 3 showed moderate activity against V. mali and S. solani. Moreover, compound 10 potently inhibited the growth of MCF‐7, SW1990, and SMMC7721 tumor cell lines with IC50 values of 4, 5, and 7 μg/ml, respectively. 相似文献
988.
Deya Eldeen Mohammed Radwan Khalaf Ali Fayez Sabry Younis Mahmoud Guoquan Lu 《Acta Physiologiae Plantarum》2010,32(5):891-904
The antioxidant status as well as protein composition of faba bean leaves infected with Bean yellow mosaic virus (BYMV) and the effect of salicylic acid application was examined in this paper. Some modifications in the antioxidant status
were observed by changing some antioxidant enzymes activities and contents of antioxidant metabolites. BYMV-infected leaves
revealed POD, CAT, APX and SOD induced activities while SA treatments could inhibit POD, CAT activities but induced SOD activity.
The enzyme activities seemed to be SA concentration dependant. Higher H2O2 and MDA concentrations were recorded in virus-infected leaves than those of the corresponding controls while treatment with
SA followed by virus inoculation caused lowering of MDA concentration and reducing the damage due to lipid peroxidation. Moreover,
because of virus infection and/or SA treatments, an increase in the amounts of phenolics and flavonoids was noticed. As compared
to the control, BYMV infection or SA application caused pronounced increase in the antioxidant activity of leaf extracts detected
by DPPH assay, indicating an increase in the amounts of antioxidant compounds occurred. To test the protein composition, the
contents of each protein fractions (soluble, insoluble and total) were analyzed and the change in protein patterns was visualized
using SDS-PAGE. The BYMV-infected bean leaves had protein contents higher than the control indicating accumulation of pathogenesis-related
proteins. Moreover, spraying SA with or without virus inoculation could accumulate soluble, insoluble and total proteins and
the pattern of increase was in accordance with SA concentration. Alterations in protein patterns were observed in faba bean
leaves (Vicia faba cv Giza 461) in response to BYMV infection and SA treatments. Because of BYMV infection and SA treatments, the protein profiles
showed new bands in comparison to the control. Some polypeptides were highly accumulated in treatments of SA followed by virus
inoculation. Changing antioxidant status and accumulation of some antioxidant metabolites as well as the pronounced alterations
in the protein composition indicate a kind of plant response against pathogen invasion and in case of SA treatment it is considered
a way by which a defence response was initiated and/or activated. 相似文献
989.
One of the most important carbohydrate-splitting enzymes is themaltase-glucoamylase which catalyzes the hydrolysis of alpha-glucosidic linkages. Maltase-glucoamylase inhibitors during the last few years have aroused medical interests in the treatment of diabetes. They contribute to a better understanding of the mechanism of maltase-glucoamylase. At present there are many different classes of maltase-glucoamylase inhibitors. This paper focuses on alkaloidal inhibitors of maltase-glucoamylase and structure-activity relationship (SAR) studies between them in order to discover some drugs with better efficiency and lower toxicity for treating diabetes. 相似文献
990.
Xin Chen Ying Gu Karnika Singh Chaowei Shang Mansoureh Barzegar Shanxiang Jiang Shile Huang 《PloS one》2014,9(12)
Maduramicin, a polyether ionophore antibiotic derived from the bacterium Actinomadura yumaensis, is currently used as a feed additive against coccidiosis in poultry worldwide. It has been clinically observed that maduramicin can cause skeletal muscle and heart cell damage, resulting in skeletal muscle degeneration, heart failure, and even death in animals and humans, if improperly used. However, the mechanism of its toxic action in myoblasts is not well understood. Using mouse myoblasts (C2C12) and human rhabdomyosarcoma (RD and Rh30) cells as an experimental model for myoblasts, here we found that maduramicin inhibited cell proliferation and induced cell death in a concentration-dependent manner. Further studies revealed that maduramicin induced accumulation of the cells at G0/G1 phase of the cell cycle, and induced apoptosis in the cells. Concurrently, maduramicin downregulated protein expression of cyclin D1, cyclin-dependent kinases (CDK4 and CDK6), and CDC25A, and upregulated expression of the CDK inhibitors (p21Cip1 and p27Kip1), resulting in decreased phosphorylation of Rb. Maduramicin also induced expression of BAK, BAD, DR4, TRADD and TRAIL, leading to activation of caspases 8, 9 and 3 as well as cleavage of poly ADP ribose polymerase (PARP). Taken together, our results suggest that maduramicin executes its toxicity in myoblasts at least by inhibiting cell proliferation and inducing apoptotic cell death. 相似文献