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131.
132.
Comparative morphology of the sagittal otolith in Serranus spp. 总被引:2,自引:0,他引:2
V. M. Tuset† A. Lombarte‡ J. A. González J. F. Pertusa MJ. Lorente§ 《Journal of fish biology》2003,63(6):1491-1504
Variations in the morphology of saccular otoliths (sagittae) among three sympatric species of the genus Serranus ( S. atricauda , S. cabrilla and S. scriba ) from the Canary Islands were investigated. Although the otolith gross morphology was similar among species, S. scriba was distinct in having a rostrum which had a slight turning at the tip and a more funnel‐like ostium. The shallower water species ( S. scriba ) had otolith and sulcus areas which were smaller than the deeper water species ( S. cabrilla and S. atricauda ). The sulcus acusticus and ostium size were correlated with the habit depth of the species, with the highest values in the deepest species, S. cabrilla . The otolith outline shape indices changed with size (total length) of the species, and allowed the separation of the species by means of a discriminate function. 相似文献
133.
134.
Identification of organelles in bacteria similar to acidocalcisomes of unicellular eukaryotes 总被引:6,自引:0,他引:6
Seufferheld M Vieira MC Ruiz FA Rodrigues CO Moreno SN Docampo R 《The Journal of biological chemistry》2003,278(32):29971-29978
Acidocalcisomes are acidic calcium storage compartments described in several unicellular eukaryotes, including trypanosomatid and apicomplexan parasites, algae, and slime molds. In this work, we report that the volutin granules of Agrobacterium tumefaciens possess properties similar to the acidocalcisomes. Transmission electron microscopy revealed that each intracellular granule was surrounded by a membrane. X-ray microanalysis of the volutin granules showed large amounts of phosphorus, magnesium, potassium, and calcium. Calcium in the volutin granules increased when the bacteria were incubated at high extracellular calcium concentration. Immunofluorescence and immunoelectron microscopy, using antisera raised against peptide sequences conserved in the A. tumefaciens proton pyrophosphatase, indicated localization in intracellular vacuoles. Purification of the volutin granules using iodixanol density gradients indicated a preferential localization of the pyrophosphatase activity in addition to high concentrations of phosphate, pyrophosphate, short- and long-chain polyphosphate, but lack of markers of the plasma membrane. The pyrophosphatase activity was potassium-insensitive and inhibited by the pyrophosphate analogs, amynomethylenediphosphonate and imidodiphosphate, by dicyclohexylcarbodiimide, and by the thiol reagent N-ethylmaleimide. Polyphosphate was also localized to the volutin granules by 4',6'-diamino-2-phenylindole staining. The organelles were acidic, as demonstrated by staining with LysoSensor blue DND-167, a dye especially used to detect very acidic compartments in cells, and cycloprodigiosin, a compound isolated from a marine bacterium that has been shown to uncouple proton pyrophosphatase activity acting as a chloride/proton symport. The results suggest that acidocalcisomes arose before the prokaryotic and eukaryotic lineages diverged. 相似文献
135.
GPS?Raghava Stephen?MJ?Searle Patrick?C?Audley Jonathan?D?Barber Geoffrey?J?BartonEmail author 《BMC bioinformatics》2003,4(1):47
Background
The alignment of two or more protein sequences provides a powerful guide in the prediction of the protein structure and in identifying key functional residues, however, the utility of any prediction is completely dependent on the accuracy of the alignment. In this paper we describe a suite of reference alignments derived from the comparison of protein three-dimensional structures together with evaluation measures and software that allow automatically generated alignments to be benchmarked. We test the OXBench benchmark suite on alignments generated by the AMPS multiple alignment method, then apply the suite to compare eight different multiple alignment algorithms. The benchmark shows the current state-of-the art for alignment accuracy and provides a baseline against which new alignment algorithms may be judged. 相似文献136.
Dairy cows often have to choose which of two sides to enter in the milking parlour. Some cows are very consistent in this choice, and it is common to assume that when these cows are more disturbed are being milked in their non-preferred side. Such disturbance might involve significantly poor welfare. In order to assess this assumption, we decided to study the behaviour and milk yield of dairy cows and their relationships with side preference in the milking parlour. The study was carried out at Cambridge University Farm, in a two-sided tandem milking parlour. The data collection followed the daily management routine. We recorded the side chosen by each cow (left or right) during 40 milking sessions. Data from 70 cows, which were present in at least 25 milking sessions (mode=36), were included in the statistical analysis. Cows' reactivity (CR) during premilking udder preparation, time spent fitting the milking cluster (FT), milk yield (MY) and duration of milking (DM) were measured. There was evident individual variation in the consistency of side choice. Individual differences (ANOVA, P<0.001) were also found in CR, FT, MY and DM; although these variables were not significantly affected by the side or the interaction animalxside (ANOVA, P>0.05). The comparison between left and right side means (paired t-test) of these variables did not show significant differences (P>0.05). We concluded that there is no evidence that the cows were discomforted or stressed when milked in the non-preferred side of the milking parlour. 相似文献
137.
Vicente Ramírez Sjoerd Van der Ent Javier García-Andrade Alberto Coego Corné MJ Pieterse Pablo Vera 《BMC plant biology》2010,10(1):199
Background
Upon appropriate stimulation, plants increase their level of resistance against future pathogen attack. This phenomenon, known as induced resistance, presents an adaptive advantage due to its reduced fitness costs and its systemic and broad-spectrum nature. In Arabidopsis, different types of induced resistance have been defined based on the signaling pathways involved, particularly those dependent on salicylic acid (SA) and/or jasmonic acid (JA). 相似文献138.
Venu M. Margam Emma W. Gachomo John H. Shukle Oluwole O. Ariyo Manfredo J. Seufferheld Simeon O. Kotchoni 《Molecular biology reports》2010,37(7):3631-3635
Genomic DNA extraction protocols generally require the use of expensive and hazardous reagents necessary for decontamination
of phenolic compounds from the extracts. In addition, they are lengthy, hindering large-scale sample extractions necessary
for high-throughput analyses. Here we describe a simple, time and cost-efficient method for genomic DNA extraction from insects.
The extracted DNA was successfully used in a Polymerase Chain Reaction (PCR), making it suitable for automation for large-scale
genetic analysis and barcoding studies. The protocol employs a single purification step to remove polysaccharides and other
contaminating compounds using a non-hazardous reagent buffer. In addition, we conducted a bioinformatics database analysis
as proof of concept for the efficiency of the DNA extraction protocol by using universal barcoding primers specific for cytochrome
c oxidase I gene to identify different arthropod specimens through Barcode of Life Database (BOLD) database search. The usefulness
of this protocol in various molecular biology and biodiversity studies is further discussed. 相似文献
139.
140.
Molecular evolution of the period gene in Drosophila athabasca 总被引:1,自引:0,他引:1
We measured nucleotide variability within and between the three semispecies
of the Drosophila athabasca complex, at the period (per) gene by using a
polymerase chain reaction-based four-cutter restriction- enzyme analysis.
The levels of polymorphism varied considerably between the three
semispecies. Our results for per, combined with previous data for X-linked
allozymes, suggest that the X chromosome in the western- northern
semispecies is less variable than expected under an equilibrium-neutral
model. Both the pattern of divergence between the semispecies and a
cladistic clustering of per haplotypes support the previously hypothesized
grouping of eastern A and eastern B as the two most recently diverged
semispecies. A 21-bp in-frame segment in the region of per which shares
sequence similarity with the neuronal development gene single minded is
deleted in all eastern A and eastern B flies examined but is present in all
of the western-northern flies and all other published per sequences.
Despite these hints that there may be significant differences at the per
gene between the semispecies, especially the western-northern group versus
the two eastern groups, there is no compelling evidence that per is
involved in the mating song differences between the semispecies.
相似文献