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871.
Increase in circulating colony-forming units-granulocyte-macrophage during large-volume leukapheresis: evaluation of a new cell separator 总被引:1,自引:0,他引:1
Peripheral blood stem cell (PBSC) collection was evaluated in two groups of normal donors who underwent large-volume leukapheresis on a blood cell separator. In Group A (n = 10), a 3-hour leukapheresis was performed. An average of 11.8 L of blood was processed with a mean flow rate of 66 mL per minute and a collection rate of 3 mL per minute. The PBSC product contained a mean 1.4 x 10(10) mononuclear cells (MNCs) (lymphocytes and monocytes), 1.27 x 10(6) colony-forming units-granulocyte-macrophage (CFUs-GM), and an average hematocrit of 4 percent (0.04). Postapheresis blood counts showed significant reductions in MNCs (19%) and platelets (45%) (p less than 0.005). Twenty-four hours later, the MNCs had returned to preapheresis levels. The platelet count returned to baseline only after 7 days. Circulating CFUs-GM remained stable for 3 days after apheresis but were increased twofold by Day 7 after apheresis (p = 0.025). Varying the product hematocrit from 1 percent (0.01) to 13.3 percent (0.13) did not change the number of CFUs-GM collected per MNC. In Group B (n = 4), an average of 18.5 L of blood was processed with a mean flow rate of 94 mL per minute and a collection rate of 3 mL per minute. The PBSC product was collected as four sequential samples and assayed for MNCs and CFUs-GM. Total MNCs averaged 1.7 x 10(10) (an increase of 21% relative to Group A) and CFUs-GM averaged 3.08 x 10(6) (an increase of 143%). Mean MNCs did not vary significantly among the four samples. However, CFUs-GM collected per minute (relative to the first sample) did show 1.26-fold (p = 0.001), 1.86-fold (p = 0.011), and 2.52-fold (p = 0.04) increases in the second, third, and fourth samples. These data suggest that MNCs and committed progenitor cells are recruited during large-volume leukapheresis. Moreover, there is a twofold increase in circulating CFUs-GM 1 week after apheresis. 相似文献
872.
873.
Intracranial circulation: preliminary clinical results with three- dimensional (volume) MR angiography 总被引:5,自引:0,他引:5
Masaryk TJ; Modic MT; Ross JS; Ruggieri PM; Laub GA; Lenz GW; Haacke EM; Selman WR; Wiznitzer M; Harik SI 《Radiology》1989,171(3):793-799
The authors assessed the clinical utility of a magnetic resonance angiography technique in the evaluation of intracranial circulation. Eighteen patients with a low likelihood of cerebrovascular disease (control group) and 40 patients with suspected cerebrovascular disease were imaged with a FISP (fast imaging with steady precession) sequence (repetition time of 50 msec, echo time of 15 msec, velocity compensation in the read and section-select directions with acceleration compensation in the read direction, 15 degrees anisotropic volume, and a 1.25-mm partition thickness). Ninety-four percent of images in the control group and 72% of images in the group with cerebrovascular disease were considered useful for diagnosis. This technique can provide accurate images of intracranial circulation and can be performed in conjunction with two-dimensional spin-echo or gradient-echo imaging. It was most useful in the evaluation of patent intracranial aneurysms, vessel displacement, and large-vessel occlusive disease. Disadvantages included limited field of view, persistent signal voids, limited spatial resolution, and inadequate depiction of lesions with slow flow. 相似文献
874.
To devise and implement an in-plane magnetic resonance angiography examination of the carotid bifurcation capable of producing high-resolution images, the authors examined 19 normal carotid arteries and 14 patients with angiographically documented disease with two flow-correction techniques: a three-gradient, velocity-refocused technique with spin-echo (SE) and gradient-echo sequences, and a four-gradient velocity- and acceleration-corrected SE technique. With use of three equal gradients in the read direction, velocity-related phase changes were minimized by placing the dephasing gradient after the 180 degree pulse and near the read gradient. Acceleration effects were minimized through the use of short echo times and cardiac gating. Both velocity- and acceleration-produced phase changes were corrected with the four-gradient scheme but at the expense of some limitations in spatial resolution. Both techniques consistently produced satisfactory images of the carotid bifurcation in healthy individuals. However, the results indicate that the present gradient-phase modulation techniques have several drawbacks, including susceptibility to patient motion, overlapping with the jugular vein, and inability to image carotid stenosis accurately due to turbulence. 相似文献
875.
Caveolin-3 in muscular dystrophy 总被引:2,自引:0,他引:2
McNally EM; de Sa Moreira E; Duggan DJ; Bonnemann CG; Lisanti MP; Lidov HGW; Vainzof M; Passos-Bueno MR; Hoffman EP; Zatz M; Kunkel LM 《Human molecular genetics》1998,7(5):871-877
The dystrophin-glycoprotein complex (DGC) serves as a link between
cytoplasmic actin, the membrane and the extracellular matrix of striated
muscle. Genetic defects in genes encoding a subset of DGC proteins result
in muscular dystrophy and a secondary decrease in other DGC proteins.
Caveolae are dynamic structures that have been implicated in a number of
functions including endocytosis, potocytosis and signal transduction.
Caveolin (VIP-21) is thought to play a structural role in the formation of
non-clathrin-coated vesicles in a number of different cell types.
Caveolin-3, or M-caveolin, was identified as a muscle- specific form of the
caveolin family. We show that caveolin-3 co- purifies with dystrophin, and
that a fraction of caveolin-3 is a dystrophin-associated protein. We
isolated the gene for human caveolin- 3 and mapped it to chromosome 3p25.
We determined the genomic organization of human caveolin-3 and devised a
screening strategy to look for mutations in caveolin-3 in patients with
muscular dystrophy. Of 82 patients screened, two nucleotide changes were
found that resulted in amino acid substitutions (G55S and C71W); these
changes were not seen in a control population. The amino acid changes map
to a functionally important domain in caveolin-3, suggesting that these are
not benign polymorphisms and instead are disease-causing mutations.
相似文献
876.
Use of a gradient intensifying screen for scoliosis radiography 总被引:1,自引:0,他引:1
877.
878.
EM Smith MRCP 《International journal of clinical practice》1993,47(6):287-288
SUMMARY This study investigated whether consultants and junior staff in geriatric medicine would make similar decisions when presented with simulated patient case histories. 相似文献
879.
880.