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Rowena M. A. Packer Anke Hendricks Holger A. Volk Nadia K. Shihab Charlotte C. Burn 《PloS one》2013,8(7)
Intervertebral disc extrusion (IVDE) is a common neurological disorder in certain dog breeds, resulting in spinal cord compression and injury that can cause pain and neurological deficits. Most disc extrusions are reported in chondrodystrophic breeds (e.g. Dachshunds, Basset Hounds, Pekingese), where selection for ‘long and low’ morphologies is linked with intervertebral discs abnormalities that predispose dogs to IVDE. The aim of this study was to quantify the relationship between relative thoracolumbar vertebral column length and IVDE risk in diverse breeds. A 14 month cross-sectional study of dogs entering a UK small animal referral hospital for diverse disorders including IVDE was carried out. Dogs were measured on breed-defining morphometrics, including back length (BL) and height at the withers (HW). Of 700 dogs recruited from this referral population, measured and clinically examined, 79 were diagnosed with thoracolumbar IVDE following diagnostic imaging ± surgery. The BL:HW ratio was positively associated with IVDE risk, indicating that relatively longer dogs were at increased risk, e.g. the probability of IVDE was 0.30 for Miniature Dachshunds when BL:HW ratio equalled 1.1, compared to 0.68 when BL:HW ratio equalled 1.5. Additionally, both being overweight and skeletally smaller significantly increased IVDE risk. Therefore, selection for longer backs and miniaturisation should be discouraged in high-risk breeds to reduce IVDE risk. In higher risk individuals, maintaining a lean body shape is particularly important to reduce the risk of IVDE. Results are reported as probabilities to aid decision-making regarding breed standards and screening programmes reflecting the degree of risk acceptable to stakeholders. 相似文献
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Suzann G. Speckman Vladimir I. Chernook Douglas M. Burn Mark S. Udevitz Anatoly A. Kochnev Alexander Vasilev Chadwick V. Jay Alexander Lisovsky Anthony S. Fischbach R. Bradley Benter 《Marine Mammal Science》2011,27(3):514-553
In spring 2006, we conducted a collaborative U.S.–Russia survey to estimate abundance of the Pacific walrus (Odobenus rosmarus divergens). The Bering Sea was partitioned into survey blocks, and a systematic random sample of transects within a subset of the blocks was surveyed with airborne thermal scanners using standard strip‐transect methodology. Counts of walruses in photographed groups were used to model the relation between thermal signatures and the number of walruses in groups, which was used to estimate the number of walruses in groups that were detected by the scanner but not photographed. We also modeled the probability of thermally detecting various‐sized walrus groups to estimate the number of walruses in groups undetected by the scanner. We used data from radio‐tagged walruses to adjust on‐ice estimates to account for walruses in the water during the survey. The estimated area of available habitat averaged 668,000 km2 and the area of surveyed blocks was 318,204 km2. The number of Pacific walruses within the surveyed area was estimated at 129,000 with 95% confidence limits of 55,000–507,000 individuals. Poor weather conditions precluded surveying in other areas; therefore, this value represents the number of Pacific walruses within about half of potential walrus habitat. 相似文献
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257.
Early origin of foraminifera suggested by SSU rRNA gene sequences 总被引:11,自引:3,他引:8
Pawlowski J; Bolivar I; Fahrni JF; Cavalier-Smith T; Gouy M 《Molecular biology and evolution》1996,13(3):445-450
Foraminifera are one of the largest groups of unicellular eukaryotes with
probably the best known fossil record. However, the origin of foraminifera
and their phylogenetic relationships with other eukaryotes are not well
established. In particular, two recent reports, based on ribosomal RNA gene
sequences, have reached strikingly different conclusions about
foraminifera's evolutionary position within eukaryotes. Here, we present
the complete small subunit (SSU) rRNA gene sequences of three species of
foraminifera. Phylogenetic analysis of these sequences indicates that they
branch very deeply in the eukaryotic evolutionary tree: later than those of
the amitochondrial Archezoa, but earlier than those of the Euglenozoa and
other mitochondria-bearing phyla. Foraminifera are clearly among the
earliest eukaryotes with mitochondria, but because of the peculiar nature
of their SSU genes we cannot be certain that they diverged first, as our
data suggest.
相似文献
258.
Membrane lipid order of sub‐synaptic T cell vesicles correlates with their dynamics and function 下载免费PDF全文
George W. Ashdown David J. Williamson Gary H.M. Soh Nathan Day Garth L. Burn Dylan M. Owen 《Traffic (Copenhagen, Denmark)》2018,19(1):29-35
During an immune response, T cells survey antigen presenting cells for antigenic peptides via the formation of an interface known as an immunological synapse. Among the complex and dynamic biophysical phenomena occurring at this interface is the trafficking of sub‐synaptic vesicles carrying a variety of proximal signalling molecules. Here, we show that rather than being a homogeneous population, these vesicles display a diversity of membrane lipid order profiles, as measured using the environmentally sensitive dye di‐4‐ANEPPDHQ and multi‐spectral TIRF microscopy. Using live‐cell imaging, vesicle tracking and a variety of small molecule drugs to manipulate components of the actin and tubulin cytoskeleton, we show that the membrane lipid order of these vesicles correlate with their dynamics. Furthermore, we show that the key proximal signalling molecule Linker for Activation of T cells (LAT) is enriched in specific vesicle populations as defined by their higher membrane order. These results imply that vesicle lipid order may represent a novel regulatory mechanism for the sorting and trafficking of signalling molecules at the immunological synapse, and, potentially, other cellular structures. 相似文献
259.
Joseph C. R. Thacker Alex L. Wilson Zak E. Hughes Matthew J. Burn Peter I. Maxwell 《Molecular simulation》2018,44(11):881-890
AbstractThe optimisation of a peptide-capped glycine using the novel force field FFLUX is presented. FFLUX is a force field based on the machine-learning method kriging and the topological energy partitioning method called Interacting Quantum Atoms. FFLUX has a completely different architecture to that of traditional force fields, avoiding (harmonic) potentials for bonded, valence and torsion angles. In this study, FFLUX performs an optimisation on a glycine molecule and successfully recovers the target density-functional-theory energy with an error of 0.89 ± 0.03 kJ mol?1. It also recovers the structure of the global minimum with a root-mean-squared deviation of 0.05 Å (excluding hydrogen atoms). We also show that the geometry of the intra-molecular hydrogen bond in glycine is recovered accurately. 相似文献
260.
Wagner A Barrows A Wijnen JT van der Klift H Franken PF Verkuijlen P Nakagawa H Geugien M Jaghmohan-Changur S Breukel C Meijers-Heijboer H Morreau H van Puijenbroek M Burn J Coronel S Kinarski Y Okimoto R Watson P Lynch JF de la Chapelle A Lynch HT Fodde R 《American journal of human genetics》2003,72(5):1088-1100
The identification of germline mutations in families with HNPCC is hampered by genetic heterogeneity and clinical variability. In previous studies, MSH2 and MLH1 mutations were found in approximately two-thirds of the Amsterdam-criteria-positive families and in much lower percentages of the Amsterdam-criteria-negative families. Therefore, a considerable proportion of HNPCC seems not to be accounted for by the major mismatch repair (MMR) genes. Does the latter result from a lack of sensitivity of mutation detection techniques, or do additional genes underlie the remaining cases? In this study we address these questions by thoroughly investigating a cohort of clinically selected North American families with HNPCC. We analyzed 59 clinically well-defined U.S. families with HNPCC for MSH2, MLH1, and MSH6 mutations. To maximize mutation detection, different techniques were employed, including denaturing gradient gel electrophoresis, Southern analysis, microsatellite instability, immunohistochemistry, and monoallelic expression analysis. In 45 (92%) of the 49 Amsterdam-criteria-positive families and in 7 (70%) of the 10 Amsterdam-criteria-negative families, a mutation was detected in one of the three analyzed MMR genes. Forty-nine mutations were in MSH2 or MLH1, and only three were in MSH6. A considerable proportion (27%) of the mutations were genomic rearrangements (12 in MSH2 and 2 in MLH1). Notably, a deletion encompassing exons 1-6 of MSH2 was detected in seven apparently unrelated families (12% of the total cohort) and was subsequently proven to be a founder. Screening of a second U.S. cohort with HNPCC from Ohio allowed the identification of two additional kindreds with the identical founder deletion. In the present study, we show that optimal mutation detection in HNPCC is achieved by combining accurate and expert clinical selection with an extensive mutation detection strategy. Notably, we identified a common North American deletion in MSH2, accounting for approximately 10% of our cohort. Genealogical, molecular, and haplotype studies showed that this deletion represents a North American founder mutation that could be traced back to the 19th century. 相似文献