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111.
Sergio E. Bermúdez Brittany A. Armstrong Lillian Domínguez Aparna Krishnavajhala Alexander R. Kneubehl Sarah M. Gunter Adam Replogle Jeannine M. Petersen Job E. Lopez 《PLoS neglected tropical diseases》2021,15(8)
Tick-borne relapsing fever (TBRF) spirochetes are likely an overlooked cause of disease in Latin America. In Panama, the pathogens were first reported to cause human disease in the early 1900s. Recent collections of Ornithodoros puertoricensis from human dwellings in Panama prompted our interest to determine whether spirochetes still circulate in the country. Ornithodoros puertoricensis ticks were collected at field sites around the City of Panama. In the laboratory, the ticks were determined to be infected with TBRF spirochetes by transmission to mice, and we report the laboratory isolation and genetic characterization of a species of TBRF spirochete from Panama. Since this was the first isolation of a species of TBRF spirochete from Central America, we propose to designate the bacteria as Borrelia puertoricensis sp. nov. This is consistent with TBRF spirochete species nomenclature from North America that are designated after their tick vector. These findings warrant further investigations to assess the threat B. puertoricensis sp. nov. may impose on human health. 相似文献
112.
Lipocalins form a widespread class of proteins involved in the transport of weakly soluble vitamins, hormones or hydrophobic molecules. β-lactoglobulin (BLG-col), a major lipocalin present in whey was purified and characterized from buffalo colostrum. The molecular weight of BLG-col as determined by Liquid chromatography -electrospray ionization mass spectrometry (LC-ESI-MS) was 18.257 kDa and the peptide mass fingerprint of the purified protein revealed 67% sequence homology to buffalo milk β-lg. The N-terminal-IIVTQ and LC-ESI-collision-induced dissociation-Electron transfer dissociation mass spectrometry/mass spectrometry analyses of doubly (m/z 1156(+2)) and triply (m/z 546(+3)) charged ion pairs corresponding to VYVEELKPTPEGDLEILLQK (41-60) and TPEVDDEALEKFDK (125-138) sequences confirmed the identity of BLG-col. Using these peptide sequences, the location of a gene encoding for BLG-col was identified on chromosome 11 at 11q28 loci of bovine genome. The unique property of the BLG-col isolated from buffalo colostrum was its strong and specific haemagglutinating activity with 'O' blood of human erythrocytes with 10,309 HAU/mg protein. The cell surface localization of BLG-col on human erythrocytes was confirmed by immunocytochemistry and the specificity of interaction was established by immunoblot analysis of human erythrocyte membrane proteins. Based on these observations, we suggest the presence of lipocalin receptor (70 kDa) on human erythrocyte membrane and the multiple sequence alignment supported structural diversity among lipocalin receptors. 相似文献
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The process of uptake of hexamerins during metamorphosis from insect haemolymph by fat body cells is reminiscent of receptor-mediated
endocytosis. Previously, we had identified a hexamerin-binding protein (HBP) and reported for the first time that uptake of
hexamerins is dependent on the phosphorylation of HBP partly by a tyrosine kinase, which is, in turn, activated by 20-hydroxyecdysone
(20E). However, the exact nature of HBP and the mechanism of interaction are still unknown. Here we report the possibility
of HBP being a GPI-anchored protein in the fat body of Achaea janata and its role in the tyrosine-kinase-mediated phosphorylation signalling. Digestion of fat body membrane preparation with
bacterial phosphatidylinositol-specific phospholipase C (PI-PLC), and the subsequent recognition by antibodies specific for
the cross-reacting determinant (CRD), revealed that HBP is glycosylphosphatidylinositol (GPI)-anchored protein and, further,
that the hexamerin binding to HBP was inhibited after digestion. Hexamerin overlay assay (HOA) of co-immunoprecipitated in vitro phosphorylated HBP showed exclusive binding to ~120 kDa protein. Lectin-binding analysis of hexamerins revealed the presence
of N-acetylgalactosamine (GalNAc) and N-acetylglucosamine (GluNAc), whereas HBP showed the presence of GalNac alone. Mild chemical deglycosylation studies and binding
interaction in the presence of sugars revealed that glycan moieties are possibly not involved in the interaction between HBP
and hexamerins. Taken together, these results suggest that HBP may be a GPI-anchored protein, and interaction and activation
of HBP is through lipid-linked non-receptor src tyrosine kinases. However, additional studies are needed to prove that HBP is a GPI-anchored protein. 相似文献
115.
Conserved bacteriophage ATP-based DNA translocation motors consist of a multimeric packaging terminase docked onto a unique procapsid vertex containing a portal ring. DNA is translocated into the empty procapsid through the portal ring channel to high density. In vivo the T4 phage packaging motor deals with Y- or X-structures in the replicative concatemer substrate by employing a portal-bound Holliday junction resolvase that trims and releases these DNA roadblocks to packaging. Here using dye-labeled packaging anchored 3.7-kb Y-DNAs or linear DNAs, we demonstrate FRET between the dye-labeled substrates and GFP portal-containing procapsids and between GFP portal and single dye-labeled terminases. We show using FRET-fluorescence correlation spectroscopy that purified T4 gp49 endonuclease VII resolvase can release DNA compression in vitro in prohead portal packaging motor anchored and arrested Y-DNA substrates. In addition, using active terminases labeled at the N- and C-terminal ends with a single dye molecule, we show by FRET distance of the N-terminal GFP-labeled portal protein containing prohead at 6.9 nm from the N terminus and at 5.7 nm from the C terminus of the terminase. Packaging with a C-terminal fluorescent terminase on a GFP portal prohead, FRET shows a reduction in distance to the GFP portal of 0.6 nm in the arrested Y-DNA as compared with linear DNA; the reduction is reversed by resolvase treatment. Conformational changes in both the motor proteins and the DNA substrate itself that are associated with the power stroke of the motor are consistent with a proposed linear motor employing a terminal-to-portal DNA grip-and-release mechanism. 相似文献
116.
A. Pavan-Kumar P. Gireesh-Babu P. P. Suresh Babu A. K. Jaiswar V. Hari Krishna K. Pani Prasasd Aparna Chaudhari S. G. Raje S. K. Chakraborty Gopal Krishna W. S. Lakra 《Molecular biology reports》2014,41(1):447-457
The elasmobranchs (sharks, rays and skates) being the extant survivors of one of the earliest offshoots of the vertebrate evolutionary tree are good model organisms to study the primitive vertebrate conditions. They play a significant role in maintaining the ecological balance and have high economic value. Due to over-exploitation and illegal fishing worldwide, the elasmobranch stocks are being decimated at an alarming rate. Appropriate management measures are necessary for restoring depleted elasmobranch stocks. One approach for restoring stocks is implementation of conservation measures and these measures can be formulated effectively by knowing the evolutionary relationship among the elasmobranchs. In this study, a total of 30 species were chosen for molecular phylogeny studies using mitochondrial cytochrome c oxidase subunit I, 12S ribosomal RNA gene and nuclear Internal Transcribed Spacer 2. Among different genes, the combined dataset of COI and 12S rRNA resulted in a well resolved tree topology with significant bootstrap/posterior probabilities values. The results supported the reciprocal monophyly of sharks and batoids. Within Galeomorphii, Heterodontiformes (bullhead sharks) formed as a sister group to Lamniformes (mackerel sharks): Orectolobiformes (carpet sharks) and to Carcharhiniformes (ground sharks). Within batoids, the Myliobatiformes formed a monophyly group while Pristiformes (sawfishes) and Rhinobatiformes (guitar fishes) formed a sister group to all other batoids. 相似文献
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Daniel Martinez-Ramirez Juan Giugni Vinata Vedam-Mai Aparna Wagle Shukla Irene A. Malaty Nikolaus R. McFarland Ramon L. Rodriguez Kelly D. Foote Michael S. Okun 《PloS one》2014,9(4)