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991.
Bassam R.S. Ali Liqing Zhou Fiona M. Graves Robert B. Freedman Gary W. Black Harry J. Gilbert Geoffrey P. Hazlewood 《FEMS microbiology letters》1995,125(1):15-22
Abstract More than 80% of the extracellular Avicelase, endoglucanase, xylanase and mannanase activities of the anaerobic fungus Piromyces were associated with a cellulose-binding complex. The complex was composed of at least 10 polypeptides ranging in size from 190 kDa to 50 kDa, and contained numerous endoglucanases, xylanases and mannanases. Multiple genes encoding each of these activities were isolated from an expressing cDNA library. 相似文献
992.
Aidan Dolan Fiona E. Jamieson Charles Cunningham Barbara C. Barnett Duncan J. McGeoch 《Journal of virology》1998,72(3):2010-2021
The genomic DNA sequence of herpes simplex virus type 2 (HSV-2) strain HG52 was determined as 154,746 bp with a G+C content of 70.4%. A total of 74 genes encoding distinct proteins was identified; three of these were each present in two copies, within major repeat elements of the genome. The HSV-2 gene set corresponds closely with that of HSV-1, and the HSV-2 sequence prompted several local revisions to the published HSV-1 sequence (D. J. McGeoch, M. A. Dalrymple, A. J. Davison, A. Dolan, M. C. Frame, D. McNab, L. J. Perry, J. E. Scott, and P. Taylor, J. Gen. Virol. 69:1531–1574, 1988). No compelling evidence for the existence of any additional protein-coding genes in HSV-2 was identified.The complete 152-kbp genomic DNA sequence of herpes simplex virus type 1 (HSV-1) was published in 1988 (56) and since then has been very widely employed in a great range of research on HSV-1. Additionally, results from this most studied member of the family Herpesviridae have fed powerfully into research on other herpesviruses. In contrast, although a substantial number of individual gene sequences have been determined for the other HSV serotype, HSV-2, the complete genome sequence for this virus has not been available hitherto. In this paper we report the sequence of the genome of HSV-2, strain HG52.At a gross level the 155-kbp genome of HSV-2 is viewed as consisting of two extended regions of unique sequence (UL and US), each of which is bounded by a pair of inverted repeat elements (TRL-IRL and IRS-TRS) (17, 66) (Fig. (Fig.1).1). There is a directly repeated sequence of some 254 bp at the genome termini (the a sequence), with one or more copies in the opposing orientation (the a′ sequence) at the internal joint between IRL and IRS (21). UL plus its flanking repeats is termed the long (L) region, and US with its flanking repeats is termed the short (S) region. In individual molecules of HSV-2 DNA, the L and S components may be linked with each in either orientation, so that DNA preparations contain four sequence-orientation isomers, one of which is defined as the prototype (66). The sequences of the terminal and internal copies of RL and of RS are considered to be indistinguishable. Open in a separate windowFIG. 1Overall organization of the genome of HSV-2. The linear double-stranded DNA is represented, with the scale at the top. The unique portions of the genome (UL and US) are shown as heavy solid lines, and the major repeat elements (TRL, IRL, IRS, and TRS) are shown as open boxes. For each pair of repeats the two copies are in opposing orientations. As indicated, TRL, UL, and IRL are regarded as comprising the L region, and IRS, US, and TRS are regarded as comprising the S region. Plasmid-cloned fragments used for sequence determination are indicated at the bottom: BamHI and HindIII fragments are indicated by B and H, respectively, followed by individual fragment designations in lowercase; KH and HK indicate KpnI/HindIII fragments as described in the text.This paper presents properties of the HSV-2 DNA sequence and our present understanding of its content of protein-coding genes and other elements. We are also interested in comparative analysis of the HSV-1 and HSV-2 genomes to examine processes of molecular evolution which have occurred since the two species diverged, and we intend to pursue this topic in a separate paper. 相似文献
993.
Heteromeric channel formation and Ca-free media reduce the toxic effect of the weaver Kir 3.2 allele
Stephen J. Tucker Mauro Pessia Andrew J. Moorhouse Fiona Gribble Frances M. Ashcroft James Maylie John P. Adelman 《FEBS letters》1996,390(3):253-257
weaver mice have a severe hypoplasia of the cerebellum with an almost complete loss of the midline granule cells. Recent genetic studies of weaver mice have identified a mutation resulting in an amino acid substitution (G156S) in the pore of the inwardly rectifying potassium channel subunit Kir 3.2. When expressed in Xenopus oocytes the weaver mutation alters channel selectivity from a potassium-selective to a nonspecific cation-selective pore. In this study we confirm by cell-attached patch-clamp recording that the mutation produces a non-selective cation channel. We also demonstrate that the cell death induced by weaver expression may be prevented by elimination of calcium from the extracellular solution as well as by coexpression with the wild-type Kir 3.2 allele, or other members of the Kir 3.0 subfamily. These results suggest that the weaver defect in Kir 3.2 may cause cerebellar cell death by cell swelling and calcium overload. Cells which express the weaver subunit, but which normally survive, may do so because of heteromeric subunit assembly with wild-type subunits of the Kir 3.0 subfamily. 相似文献
994.
Fiona J. Couper Olaf H. Drummer 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1996,685(2):1869
A solid-phase extraction procedure is described for the simultaneous determination of terbutaline, salbutamol and fenoterol in human postmortem whole blood, using gas chromatography-electron impact mass spectrometry. The limit of quantitation in 1 ml of blood was 1 ng/ml for all analytes. A linear response was observed over the concentration ranges tested, covering both low and high concentration of each drug. The recoveries in postmortem blood were: terbutaline, 88%; salbutamol, 86%; fenoterol, 92%; orciprenaline (internal standard), 86%. Coefficients of variation for both intra-assay precision and inter-assay reproducibility ranged between 2.2 and 13.0% for all analytes. This method is sensitive and selective, and has been applied successfully to over 60 postmortem blood specimens. 相似文献
995.
C J Savory M A Mitchell 《Comparative biochemistry and physiology. A, Comparative physiology》1991,100(4):969-974
1. Rates of absorption of two hexose (D-glucose and D-galactose) and two pentose (D-xylose and D-arabinose) sugars were measured by in vivo perfusion, in jejunum, ileum and (distal) caecum, in immature hens conditioned to either a standard (ST) or "high fibre" (ST + 20% grass) diet. 2. Each bird was tested in one intestinal segment with all four (U-14C-labelled, 10 mM) sugars, with either the hexoses preceding the pentoses or vice versa. 3. With all treatments, absorption rates of the hexoses were alike, as were those of the pentoses. Hexose absorption was twice as fast as pentose absorption in jejunum and ileum with both dietary pretreatments, whereas in caecum hexose and pentose rates were similarly high, except when pentose (and its associated fluid transfer) was apparently inhibited by prior hexose absorption with the ST diet. 4. With the ST diet, hexose absorption (per unit length and dry weight) was faster in caecum than in jejunum and ileum, and pentose absorption was also fastest in caecum when all pentose data from testing after hexose were excluded. 5. With the ST/grass diet, hexose absorption was faster in jejunum than in ileum and caecum when expressed per unit length, and pentose absorption was fastest in caecum on a dry weight basis. 6. Hexose absorption was faster in jejunum and slower in caecum with the ST/grass pretreatment than with ST. However, the dietary comparison was not conclusive because it involved birds form (two) different hatches (of similar age and weight) tested at different times. 相似文献
996.
Jane Willoughby Fiona E. Craig Stephen A. K. Harvey John B. Clark 《Journal of neurochemistry》1989,52(3):896-901
The possibility that 2-oxoglutarate may supply acetyl units for the cytosolic synthesis of acetylcholine in rat brain synaptosomes was investigated. The contribution of [14C]2-oxoglutarate to the synaptosomal synthesis of [14C]acetylcholine was found to be negligible despite evidence for its uptake and oxidation. The activity of the enzymes NADP-isocitrate dehydrogenase (EC 1.1.1.42), aconitate hydratase (EC 4.2.1.3), and ATP citrate-lyase (EC 4.1.3.8) were measured in the synaptosol. NADP-isocitrate dehydrogenase and aconitate hydratase are present at three- to 1.5-fold higher activities than ATP citrate-lyase. It seems likely that these enzymes contribute to the metabolism of citrate and prevent detectable formation of cytosolic acetyl-CoA from exogenously added 2-oxoglutarate (or citrate). The data further suggest that ATP citrate-lyase may in part be associated with the mitochondrial fraction. 相似文献
997.
Fiona M. Ellard Andres Cabello George P. C. Salmond 《Molecular & general genetics : MGG》1989,218(3):491-498
Summary Using transformation and conjugal mobilization, plasmids carrying the lamB gene of Escherichia coli were transferred to a range of Erwinia strains. The resultant strains were infected with 467, and kanamycin resistant transductants were screened for various mutant phenotypes including auxotrophy and altered extracellular enzyme activities. Reversion analysis suggested that most mutant phenotypes were due to Tn5 insertion. The applicability of the techniques was highly strain dependent. However a rapid and simple route to mutant isolation was obtained, which could allow the use of other -related genetic techniques in several important species which, to date, have not been genetically manipulated. 相似文献
998.
Ajit S. Bhown John E. Mole Fiona Hunter J. Claude Bennett 《Analytical biochemistry》1980,103(1):184-190
An improved electrodialysis procedure has been developed to recover quantitatively proteins from sodium dodecyl sulfate (SDS)-polyacrylamide gels. The efficiency of the method has been demonstrated successfully on H-2Kk, β2-microglobulin, complement factor D, and viral structural protein p27. The results indicate that yields exceeding 93% are obtainable, and that extended amino acid sequences of the eluted proteins in microgram quantities can be obtained in the presence of SDS without intrinsic and/or extrinsic labeling with radioisotopes. 相似文献
999.
Hongwei Dou Jie Xu Zhaohui Wang Annabel N Smith Manoocher Soleimani Fiona E Karet John H Greinwald Daniel Choo 《The journal of histochemistry and cytochemistry》2004,52(10):1377-1384
The endolymph in the endolymphatic sac (ES) is acidic (pH 6.6-7). Maintaining this acidic lumen is believed to be important for the normal function of the ES. The acid-base regulation mechanisms of the ES are unknown. Here we investigated the expression patterns of acid-base regulators, including vacuolar (v)H+-ATPase (proton pump), carbonic anhydrase (CA) II, and pendrin in the murine ES epithelium by immunohistochemistry (IHC) and compared their expression patterns by double immunostaining. We found that pendrin and vH+-ATPase were co-localized in the apical membrane of a specific type of ES epithelial cell. Pendrin- and vH+-ATPase-positive cells also expressed cytoplasmic CA II. Co-expression of pendrin, vH+-ATPase, and CA II in the same subgroup of ES cells suggests that this specific type of ES cell is responsible for the acid-base balance processes in the ES and pendrin, vH+-ATPase, and CA II are involved in these processes. 相似文献
1000.
In this article we review current literature on cross-modal recognition and present new findings from our studies on object and scene recognition. Specifically, we address the questions of what is the nature of the representation underlying each sensory system that facilitates convergence across the senses and how perception is modified by the interaction of the senses. In the first set of our experiments, the recognition of unfamiliar objects within and across the visual and haptic modalities was investigated under conditions of changes in orientation (0 degrees or 180 degrees ). An orientation change increased recognition errors within each modality but this effect was reduced across modalities. Our results suggest that cross-modal object representations of objects are mediated by surface-dependent representations. In a second series of experiments, we investigated how spatial information is integrated across modalities and viewpoint using scenes of familiar, 3D objects as stimuli. We found that scene recognition performance was less efficient when there was either a change in modality, or in orientation, between learning and test. Furthermore, haptic learning was selectively disrupted by a verbal interpolation task. Our findings are discussed with reference to separate spatial encoding of visual and haptic scenes. We conclude by discussing a number of constraints under which cross-modal integration is optimal for object recognition. These constraints include the nature of the task, and the amount of spatial and temporal congruency of information across the modalities. 相似文献