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排序方式: 共有358条查询结果,搜索用时 71 毫秒
71.
Pl Munk Dc Morris Dg Connell Jr Mayo Mj Lee DF Sallomi 《Journal of Medical Imaging and Radiation Oncology》1999,43(2):160-164
Liver biopsy is still most commonly done via the percutaneous route; however, increasingly, transvascular venous liver biopsy has been used in patients with bleeding disorders. Although the jugular route is now generally favoured, a transfemoral route can be a useful alternative technique when the jugular route is not available. We describe the transfemoral technique and outline a number of commonly encountered problems and complications and suggested methods of addressing them. 相似文献
72.
Sonja J McKeown Vivian M Lee Marianne Bronner-Fraser Donald F Newgreen Peter G Farlie 《Developmental dynamics》2005,233(2):430-444
SoxE genes (Sox8, Sox9, and Sox10) are early response genes to neural crest induction. Although the early role of Sox9 has been examined in chick and frog, later roles in neural crest migration and differentiation remain largely unexplored. We first examined which SoxE genes were expressed in trunk neural crest cells and then investigated their function using in ovo electroporation. The results of this analysis reveal that Sox10 is present in migrating neural crest cells, whereas other SoxE genes are only expressed transiently after induction. Ectopic expression of Sox10 in the neural tube at trunk level induced expression of HNK-1 in neuroepithelial cells followed by extensive emigration from all levels of the dorsoventral neuraxis, including the floor plate. Sox10-expressing cells failed to express neuronal, Schwann, or melanocyte markers up to 6 days posttransfection (E8), suggesting these cells were maintained in an undifferentiated state. Overexpression of Sox8 or Sox9 had similar but not identical effects on neuroepithelial cells. These results show that high levels of Sox10, Sox9, or Sox8 expression in the neural tube are capable of inducing a migratory neural crest-like phenotype even in the absence of dorsal signals and can maintain these cells in an undifferentiated state. 相似文献
73.
Pieter-Jan DF Guns Jan Hendrickx Tim Van Assche Paul Fransen Hidde Bult 《British journal of pharmacology》2010,159(2):326-336
Background and purpose:
P2Y nucleotide receptors are involved in the regulation of vascular tone, smooth muscle cell (SMC) proliferation and inflammatory responses. The present study investigated whether they are involved in atherosclerosis.Experimental approach:
mRNA of P2Y receptors was quantified (RT-PCR) in atherosclerotic and plaque-free aorta segments of apolipoprotein E-deficient (apoE–/–) mice. Macrophage activation was assessed in J774 macrophages, and effects of non-selective purinoceptor antagonists on atherosclerosis were evaluated in cholesterol-fed apoE–/– mice.Key results:
P2Y6 receptor mRNA was consistently elevated in segments with atherosclerosis, whereas P2Y2 receptor expression remained unchanged. Expression of P2Y1 or P2Y4 receptor mRNA was low or undetectable, and not influenced by atherosclerosis. P2Y6 mRNA expression was higher in cultured J774 macrophages than in cultured aortic SMCs. Furthermore, immunohistochemical staining of plaques demonstrated P2Y6-positive macrophages, but few SMCs, suggesting that macrophage recruitment accounted for the increase in P2Y6 receptor mRNA during atherosclerosis. In contrast to ATP, the P2Y6-selective agonist UDP increased mRNA expression and activity of inducible nitric oxide synthase and interleukin-6 in J774 macrophages; this effect was blocked by suramin (100–300 µM) or pyridoxal-phosphate-6-azophenyl-2′-4′-disulphonic acid (PPADS, 10–30 µM). Finally, 4-week treatment of cholesterol-fed apoE–/– mice with suramin or PPADS (50 and 25 mg·kg−1·day−1 respectively) reduced plaque size, without changing plaque composition (relative SMC and macrophage content) or cell replication.Conclusions and implications:
These results suggest involvement of nucleotide receptors, particularly P2Y6 receptors, during atherosclerosis, and warrant further research with selective purinoceptor antagonists or P2Y6 receptor-deficient mice. 相似文献74.
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Dietary energy restriction was previously shown to be effective in
preventing a wide range of experimentally induced cancers. Studies were
conducted to assess the influence on pancreatic carcinogenesis of dietary
energy restrictions (reduced fat and carbohydrate) of 10%, 20% or 40% in
comparison with control in Syrian hamsters treated with N-
nitrosobis(2-oxopropyl)amine (BOP). Two carcinogenesis studies were
conducted. One used a single treatment with 20 mg BOP/kg body weight and
followed hamsters for 102 weeks following treatment, and the other used
three weekly treatments of 20 mg BOP/kg body weight and followed hamsters
for 45 weeks after treatment. Hamsters were fed control or energy
restricted diet beginning the week following the last BOP treatment.
Pancreatic carcinomas were induced in 9-18% of the hamsters in the first
experiment and in 59-66% of the animals in the second. Dietary energy
restriction did not influence carcinoma incidence in either study, and in
the second experiment the multiplicity of tumors was higher in the 40%
energy restriction (ER) group than in control hamsters. Plasma
corticosterone was suppressed by BOP treatment, particularly in the 20% and
40% ER hamsters in the second experiment, and diet or BOP treatment did not
significantly alter plasma cortisol. Pancreatic protein kinase Czeta
measured by Western blot was highest in the cytosol and particulate
fractions of the 40% ER hamsters in the first experiment. These results
indicate that dietary energy restriction is not effective in the prevention
of BOP induced pancreatic carcinogenesis in the Syrian hamster.
相似文献
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Adam Bryant Catalina A Palma Vivek Jayaswal Yee Wa Yang Mark Lutherborrow David DF Ma 《Molecular cancer》2012,11(1):1-9