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72.
Direct shoot formation in spontaneously occurring root pseudonodules of alfalfa (Medicago sativa L.)
P. Sarul M. Vlahova A. Ivanova A. Atanassov 《In vitro cellular & developmental biology. Plant》1995,31(1):21-25
Summary A simple and rapid procedure for direct organogenesis from root nodulelike structures of alfalfa (Medicago sativa L.) line SGg, spontaneously induced on growth regulator-free Gamborg (B5) medium, was developed. Prolific adventitious shoot initiation was obtained using a combination of 1.0 mg/liter TIBA and
0.5 mg/liter 2iP. Transfer of shoots to a medium containing 0.5 mg/liter ABA and reduced concentration of TIBA (0.5 mg/liter)
before rooting markedly stimulated shoot development. Regenerated shoots rooted easily and revealed the early appearance of
nodulelike structures on basal medium (B5) lacking growth regulators. Analysis of endogenous growth regulator levels of SGg roots maintained on growth regulators free
media, showed that spontaneous shoot appearances was correlated with high cytokinin-to-auxin ratios. 相似文献
73.
Ivanova TI Agalakova NI Gusev GP 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》2006,145(1):60-67
Four structurally different protein phosphatases (PPs) inhibitors - fluoride, calyculin A, okadaic acid and cantharidin--were tested for their ability to modulate unidirectional Na(+) influx in rat red blood cells. Erythrocytes were incubated at 37 degrees C in isotonic and hypertonic media containing 1 mM ouabain and (22)Na in the absence or presence of PP inhibitors. Exposure of the cells to 20 mM fluoride or 50 nM calyculin A for 1 h under isosmotic conditions caused a significant stimulation of Na(+) influx, whereas addition of 200 microM cantharidin or 100 nM okadaic acid had no effect. After 2 h of treatment, however, all these PPs blockers significantly enhanced Na(+) transport in rat erythrocytes. Selective inhibitors of PP-1 and PP-2A types, calyculin A, cantharidin and okadaic acid, produced similar ( approximately 1.2-1.4-fold) stimulatory effects on Na(+) influx in the cells. Activation of Na(+) influx was unchanged with increasing calyculin A concentration from 50 to 200 nM. No additive stimulation of Na(+) influx was observed when the cells were treated with combination of 20 mM fluoride and 50 nM calyculin A. Na(+) influx induced by PPs blockers was inhibited by 1 mM amiloride and 200 muM bumetanide approximately in the equal extent, indicating the involvement of Na(+)/H(+) exchange and Na-K-2Cl cotransport in sodium transport through rat erythrocytes membrane. Activation of Na(+) transport in the cells induced by calyculin A and fluoride was associated with increase of intracellular Na(+) content. Shrinkage of the rat erythrocytes resulted in 2-fold activation of Na(+) influx. All tested PPs inhibitors additionally activated the Na(+) influx by 70-100% above basal shrinkage-induced level. Amiloride and bumetanide have diminished both the shrinkage-induced and PPs-inhibitors-induced Na(+) influxes. Thus, our observations clearly indicate that activities of Na(+)/H(+) exchanger and Na-K-2Cl cotransporter in rat erythrocytes are regulated by protein phosphatases and stimulated when protein dephosphorylation is inhibited. 相似文献
74.
75.
Suen G Weimer PJ Stevenson DM Aylward FO Boyum J Deneke J Drinkwater C Ivanova NN Mikhailova N Chertkov O Goodwin LA Currie CR Mead D Brumm PJ 《PloS one》2011,6(4):e18814
Fibrobacter succinogenes is an important member of the rumen microbial community that converts plant biomass into nutrients usable by its host. This bacterium, which is also one of only two cultivated species in its phylum, is an efficient and prolific degrader of cellulose. Specifically, it has a particularly high activity against crystalline cellulose that requires close physical contact with this substrate. However, unlike other known cellulolytic microbes, it does not degrade cellulose using a cellulosome or by producing high extracellular titers of cellulase enzymes. To better understand the biology of F. succinogenes, we sequenced the genome of the type strain S85 to completion. A total of 3,085 open reading frames were predicted from its 3.84 Mbp genome. Analysis of sequences predicted to encode for carbohydrate-degrading enzymes revealed an unusually high number of genes that were classified into 49 different families of glycoside hydrolases, carbohydrate binding modules (CBMs), carbohydrate esterases, and polysaccharide lyases. Of the 31 identified cellulases, none contain CBMs in families 1, 2, and 3, typically associated with crystalline cellulose degradation. Polysaccharide hydrolysis and utilization assays showed that F. succinogenes was able to hydrolyze a number of polysaccharides, but could only utilize the hydrolytic products of cellulose. This suggests that F. succinogenes uses its array of hemicellulose-degrading enzymes to remove hemicelluloses to gain access to cellulose. This is reflected in its genome, as F. succinogenes lacks many of the genes necessary to transport and metabolize the hydrolytic products of non-cellulose polysaccharides. The F. succinogenes genome reveals a bacterium that specializes in cellulose as its sole energy source, and provides insight into a novel strategy for cellulose degradation. 相似文献
76.
Chertkov O Sikorski J Nolan M Lapidus A Lucas S Del Rio TG Tice H Cheng JF Goodwin L Pitluck S Liolios K Ivanova N Mavromatis K Mikhailova N Ovchinnikova G Pati A Chen A Palaniappan K Djao OD Land M Hauser L Chang YJ Jeffries CD Brettin T Han C Detter JC Rohde M Göker M Woyke T Bristow J Eisen JA Markowitz V Hugenholtz P Klenk HP Kyrpides NC 《Standards in genomic sciences》2011,4(1):13-22
Thermomonospora curvata Henssen 1957 is the type species of the genus Thermomonospora. This genus is of interest because members of this clade are sources of new antibiotics, enzymes, and products with pharmacological activity. In addition, members of this genus participate in the active degradation of cellulose. This is the first complete genome sequence of a member of the family Thermomonosporaceae. Here we describe the features of this organism, together with the complete genome sequence and annotation. The 5,639,016 bp long genome with its 4,985 protein-coding and 76 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project. 相似文献
77.
L. P. Smirnova N. V. Krotenko E. V. Grishko N. M. Krotenko V. M. Alifirova S. A. Ivanova 《Biochemistry (Moscow) Supplemental Series B: Biomedical Chemistry》2011,5(1):76-80
Activity of erythrocyte glutathione peroxidase (GPx), glutathione reductase (GR), glutathione transferase (GT), glucose-6-phosphate
dehydrogenase (G6PDH), catalase and superoxide dismutase (SOD), the level of erythrocyte malonic dialdehyde (MDA) and also
total antioxidant activity of blood serum were studied in patients with different types of multiple sclerosis (MS). Investigation
of peripherical blood was carried out on the first day of admission to the hospital and after the standard therapy with copaxone.
During the whole period of observation all MS patients had a high level of MDA and activity of erythrocyte GP compared with
a control group. Other erythrocyte antioxidant enzymes and total antioxidant activity of blood serum exhibited weak positive
dynamics in patients with relapsing-remitting multiple sclerosis (RRMS). The pathological decrease of antioxidant system activity
in patients with secondary progressive multiple sclerosis (SPMS) was more pronounced and remained unchanged after the treatment.
This is consistent with a more severe clinical course of this disease. 相似文献
78.
M. V. Il’ina A. V. Timofeeva V. T. Ivanova E. I. Burtseva L. A. Baratova I. Yu. Sapurina G. S. Katrukha 《Applied Biochemistry and Microbiology》2012,48(8):699-704
A modern nanomaterial made of Taunit multiwalled carbon nanotubes (MWCNTs) was used for the first time to adsorb and desorb gramicidin S and teicoplanin A2 polypeptide antibiotics. Taunit was found to absorb efficiently antibiotics under particular conditions when MWCNTs were taken in excess at 20°C for 18 h. The desorption efficiency depended on the eluent content and the structure of antibiotics. The teicoplanin A2 antibiotic was eluted with a higher yield because of its higher polarity compared to gramicidin S (86% against 65% of the total Taunit-bound antibiotic). 相似文献
79.
Fourteen days-old bean plants, grown on sand with Knop's nutrient solution were subjected to water stress (three days without
irrigation). The stress led to a decrease in almost all lipid classes except phospholipids in the primary leaves. The content
of palmitic acid increased, and that of the linolenic acid decreased. An increase of hexadecenoic acid in phospholipids was
also observed. Rewatering for 24 h led to the recovery of the stressed plants including that of the photosynthetic apparatus,
but the changes in the lipid composition were insignificant. The spraying of the plants before and after the water stress
with 5 × 10-6 M solution of the phenylurea cytokinin 4-PU-30 alleviated negative effect of water stress on the lipid membrane
composition permitting the plants to resist the harmful environment.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
80.