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991.
Malik Yousef Mohamed Ketany Larry Manevitz Louise C Showe Michael K Showe 《BMC bioinformatics》2009,10(1):337
Background
Classification using microarray datasets is usually based on a small number of samples for which tens of thousands of gene expression measurements have been obtained. The selection of the genes most significant to the classification problem is a challenging issue in high dimension data analysis and interpretation. A previous study with SVM-RCE (Recursive Cluster Elimination), suggested that classification based on groups of correlated genes sometimes exhibits better performance than classification using single genes. Large databases of gene interaction networks provide an important resource for the analysis of genetic phenomena and for classification studies using interacting genes. 相似文献992.
Two experiments have been conducted, one in semi-solid Hoagland nutrient medium and the other in shallow pots containing saline soil. N2-fixing bacteria belonging toAzospirillum, Azotobacter, Klebsiella andEnterobacter were inoculated separately on kallar grass grown in semi-solid nutrient medium. It was shown that inoculation affects root proliferation and also results in15N isotopic dilution. The % Ndfa ranged from 47–70 whereas no significant effect on the total nitrogen uptake was observed. The bacterial colonization of the root surface and the presence of enteric bacteria inside the root hair cells is reported. In a soil pot experiment, non-N2-fixingPolypogon monspeliensis was used as a reference plant (control). A treatment receiving a high rate of nitrogen was also used as a non-N2-fixing control.15N-labelled ammonium sulphate at 20 kg N ha–1 and 90 kg N ha–1 was used. The % Ndfa in the aerial parts of kallar grass was 12–15 whenP. monspeliensis was used as reference plant whereas 37–39% Ndfa was estimated when the treatment receiving high nitrogen fertilizer was used as a non-N2-fixing control. These investigations revealed some problems of methodology which are discussed. 相似文献
993.
994.
Molecular sieving characteristics of the cultured endothelial monolayer 总被引:10,自引:0,他引:10
A Siflinger-Birnboim P J Del Vecchio J A Cooper F A Blumenstock J M Shepard A B Malik 《Journal of cellular physiology》1987,132(1):111-117
We examined the selectivity of the bovine pulmonary artery endothelial monolayer in vitro to molecules of different sizes. The cultured bovine pulmonary endothelial monolayer was grown on a gelatinized filter and the transendothelial transport was studied by determining the permeability of molecules ranging from 182 to 340,000 daltons under diffusion conditions. The permeabilities across the cultured bovine endothelium were modeled according to cylindrical pore theory. The data were best fit by a two-pore model with radii 65 A and 304 A and a ratio of small to large pores of 160:1. The results indicate that the cultured endothelial monolayer is a selective barrier to molecules of different sizes and that the molecular selectivity is consistent with a diffusional pathway through endothelial pore equivalents. The cultured endothelial monolayer is a useful system for studying the permeability characteristics of the endothelial barrier. 相似文献
995.
996.
Malik SS Luthra A Srivastava SK Ramachandran R 《Biochemical and biophysical research communications》2008,375(3):465-470
The Mycobacterium tuberculosis UsfX protein is an anti-sigma factor which regulates its cognate sigma factor SigF. UsfX shares low sequence homology with other anti-sigma factors making it difficult to identify the nucleotide binding site and characterize its properties. We have identified that the NTP binding site occurs close to Trp106 and the area around the nucleotide binding site is predominantly negatively charged. UsfX binds to a variety of nucleotides unlike other reported anti-sigma factors and exhibits an unusual dual NTPase activity. In silico computational experiments have identified a XGSFS motif close to the nucleotide binding site for metal ion binding. This motif is analogous to the DXSXS motif reported earlier in the human integrin CR3 protein superfamily. Overall, the experiments suggest that the M. tuberculosis UsfX represents a distinct anti-sigma factor family with a novel nucleotide binding motif. 相似文献
997.
We investigated the phase-dependent effects of light wavelength on photoperiodic clock in the migratory blackheaded bunting. Two experiments were performed, employing a skeleton paradigm (6 hours light : 6 hours darkness : 1 hour light : 11 hours darkness; 6L : 6D : 1L : 11D) at 37 ± 2 lux intensity. In the experiment 1, both 6 and 1 h light pulses were given at the same wavelength, 500 nm (green) or 650 nm (red). A group exposed to both pulses of white light served as control. In the experi-ment 2, the two light pulses were given at two different wavelengths, 6 h at 500 nm (green) and 1 h at 640 nm (red) in one group or vice-versa in the other. There was almost no photoinduction when both light pulses in experiment 1, or 1 h light pulse in experiment 2, were green. On the other hand, birds fattened and testes recrudesced when both the light pulses in experiment 1, or 1 h light pulse in experiment 2, were red. Birds receiving both pulses of white light in experiment 1 showed an intermediate response. Taken together, these results indicate that the photoperiodic clock in buntings is differentially responsive at its various circadian phases to different light wavelengths. 相似文献
998.
Abha Kathuria Anjali Gupta Nivedita Priya Prabhjot Singh Hanumantharao G. Raj Ashok K. Prasad Virinder S. Parmar Sunil K. Sharma 《Bioorganic & medicinal chemistry》2009,17(4):1550-1556
Calreticulin Transacetylase (CRTAase) catalyzes the transfer of acetyl groups from polyphenolic acetates (PAs) to the receptor proteins and modulates their biological activities. CRTAase was conveniently assayed by the irreversible inhibition of cytosolic glutathione S-transferase (GST) by the model acetoxycoumarin, 7,8-diacetoxy-4-methylcoumarin (DAMC). We have studied earlier, the influence of acetoxy groups on the benzenoid ring, the effect of reduction of double bond at C-3 and C-4 position, the effect of methyl/phenyl group at C-4, and the influence of position of carbonyl group with respect to oxygen heteroatom in the benzopyran nucleus, for the catalytic activity of CRTAase. In this communication, we have extended our previous work; wherein we studied the influence of an alkyl group (ethyl, hexyl and decyl) at the C-3 position of the acetoxy coumarins on the CRTAase activity. The substitution at C-3 position of coumarin nucleus resulted in the reduction of CRTAase activity and related effects. Accordingly the formation of NO in platelets by C-3 alkyl substituted acetoxy coumarins was found to be much less compared to the unsubstituted analogs. In addition the alkyl substitution at C-3 position exhibited the tendency to form radicals other than NO. 相似文献
999.
Ashok Sharma Sudeep Roy Kumar Parijat Tripathi Pratibha Roy Manoj Mishra Feroz Khan Abha Meena 《Bioinformation》2009,4(2):66-70
Metal ion binding domains are found in proteins that mediate transport, buffering or detoxification of metal ions. The objective of the study is to
design and analyze metal binding motifs against the genes involved in phytoremediation. This is being done on the basis of certain pre-requisite
amino-acid residues known to bind metal ions/metal complexes in medicinal and aromatic plants (MAP''s). Earlier work on MAP''s have shown
that heavy metals accumulated by aromatic and medicinal plants do not appear in the essential oil and that some of these species are able to grow
in metal contaminated sites. A pattern search against the UniProtKB/Swiss-Prot and UniProtKB/TrEMBL databases yielded true positives in
each case showing the high specificity of the motifs designed for the ions of nickel, lead, molybdenum, manganese, cadmium, zinc, iron, cobalt
and xenobiotic compounds. Motifs were also studied against PDB structures. Results of the study suggested the presence of binding sites on the
surface of protein molecules involved. PDB structures of proteins were finally predicted for the binding sites functionality in their respective
phytoremediation usage. This was further validated through CASTp server to study its physico-chemical properties. Bioinformatics implications
would help in designing strategy for developing transgenic plants with increased metal binding capacity. These metal binding factors can be used
to restrict metal update by plants. This helps in reducing the possibility of metal movement into the food chain. 相似文献
1000.
Adiponectin,biomarkers of inflammation and changes in cardiac autonomic function: Whitehall II study
Christian?Stevns?HansenEmail authorView authors OrcID profile Dorte?Vistisen Marit?Eika?J?rgensen Daniel?R.?Witte Eric?J.?Brunner Adam?G.?Tabák Mika?Kivim?ki Michael?Roden Marek?Malik Christian?Herder 《Cardiovascular diabetology》2017,16(1):153