全文获取类型
收费全文 | 1246篇 |
免费 | 89篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 27篇 |
妇产科学 | 123篇 |
基础医学 | 228篇 |
口腔科学 | 49篇 |
临床医学 | 76篇 |
内科学 | 226篇 |
皮肤病学 | 27篇 |
神经病学 | 48篇 |
特种医学 | 129篇 |
外科学 | 116篇 |
综合类 | 28篇 |
预防医学 | 94篇 |
眼科学 | 33篇 |
药学 | 67篇 |
中国医学 | 1篇 |
肿瘤学 | 75篇 |
出版年
2021年 | 12篇 |
2020年 | 12篇 |
2019年 | 12篇 |
2018年 | 22篇 |
2017年 | 15篇 |
2016年 | 22篇 |
2015年 | 24篇 |
2014年 | 26篇 |
2013年 | 42篇 |
2012年 | 37篇 |
2011年 | 56篇 |
2010年 | 51篇 |
2009年 | 57篇 |
2008年 | 48篇 |
2007年 | 75篇 |
2006年 | 51篇 |
2005年 | 45篇 |
2004年 | 47篇 |
2003年 | 34篇 |
2002年 | 44篇 |
2001年 | 30篇 |
2000年 | 38篇 |
1999年 | 43篇 |
1998年 | 27篇 |
1997年 | 42篇 |
1996年 | 35篇 |
1995年 | 23篇 |
1994年 | 20篇 |
1993年 | 19篇 |
1992年 | 12篇 |
1991年 | 16篇 |
1990年 | 21篇 |
1989年 | 34篇 |
1988年 | 31篇 |
1987年 | 19篇 |
1986年 | 21篇 |
1985年 | 22篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 13篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 11篇 |
1976年 | 11篇 |
1975年 | 6篇 |
1974年 | 6篇 |
1970年 | 7篇 |
1969年 | 10篇 |
1968年 | 7篇 |
排序方式: 共有1353条查询结果,搜索用时 15 毫秒
1.
2.
3.
On the basis of our experiences the selection of diagnostic methods for chronic odontogenic sinusitis is discussed. The selection is based on the primary sign, the reduced transparency of the sinus, detected with conventional radiography. Its purpose is the determination of the extent and nature of the opacity. Conventional methods, contrast investigations, conventional and computed tomography are used. 相似文献
4.
5.
Picotamide inhibition of excess in vitro thromboxane B2 release by colorectal mucosa in inflammatory bowel disease. 总被引:1,自引:0,他引:1
Collins CE Benson MJ Burnham WR Rampton DS 《Alimentary pharmacology & therapeutics》1996,10(3):315-320
BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease. 相似文献
6.
Computed tomography (CT) allows the differentiation of tissues by measurement of their roentgenologic densities. There are a few controversial literature data on the roentgenologic densities of the parotid and submandibular glands. These differences are, in our opinion, due to several factors: 1. The complex anatomic structure of the facial region of the skull, that demands an exact centering. In daily practice the respective imaging parameters are not always kept constant (including partial volume effects), thus introducing density errors. 2. Metallic prostheses and obturators as well as the high-density bones of the facial skull cause artefacts that impair image quality and density measurements. 3. The small density differences between the salivary glands and the adjacent soft tissues makes their differentiation difficult. 4. Different devices and parameters are used for scanning, resulting in different densities. Considering these facts, we have devised a complex method for the investigation of the parotid and mandibular salivary glands. 相似文献
7.
8.
N. V. Dimitrov M. B. Hay S. Siew D. A. Hudler L. J. Charamella D. E. Ullrey 《The American journal of pathology》1987,126(2):376-383
Adriamycin-induced cardiomyopathy in rabbits was produced by intravenous injections of the drug with a short therapeutic schedule (3 mg/kg body wt administered as four intermittent doses). Animals receiving selenium supplementation of Adriamycin showed preservation of the normal pattern of the heart histologic picture. The protective effect of selenium was accompanied by increased selenium levels in the plasma and the heart muscle. An eventual interaction between the antitumor effect of Adriamycin and the protective effect of selenium was ruled out by in vitro experiments using the L1210 cell line. Selenium did not abrogate the antiproliferative effect of Adriamycin when the cells were treated simultaneously with both agents. The results from this study indicate that Adriamycin-induced cardiotoxicity could be prevented by selenium if the animals were pretreated with selenium, rather than simultaneous administration of both agents. The mechanism of this effect is not entirely understood. 相似文献
9.
10.
Identification of two mutations in a compound heterozygous child with dihydrolipoamide dehydrogenase deficiency 总被引:1,自引:0,他引:1
Hong YS; Kerr DS; Craigen WJ; Tan J; Pan Y; Lusk M; Patel MS 《Human molecular genetics》1996,5(12):1925-1930
An infant girl with elevated blood lactate, pyruvate, and plasma
branched-chain amino acids was diagnosed with dihydrolipoamide
dehydrogenase (E3; dihydrolipoamide: NAD+ oxidoreductase, EC 1.8.1.4)
deficiency. Activities of the pyruvate dehydrogenase complex and E3 from
patient were 26 and 2% of controls in blood lymphocytes, and 11 and 14% in
cultured skin fibroblasts, respectively. Western blot analysis demonstrated
that the amount of E3 protein in fibroblasts from the patient and her
father was about half of controls, while Northern blot analysis showed
normal amounts of E3 RNA. DNA sequencing of cloned full-length E3 cDNAs
from the patient revealed two mutations in separate alleles. One is a
single base insertion of an extra adenine in the last codon of the leader
peptide sequence (TAC-->TAAC) leading to a nonsense mutation which
results in the premature termination of the precursor E3 polypeptide
(Y35X). The other is a missense mutation due to substitution of guanine for
adenine, causing an Arg-->Gly substitution at amino acid 460 of the
mature protein (R460G) which triggers the loss of E3 activity probably by
structural change in the E3 dimer. DNA sequencing of E3 cDNAs from the
parents demonstrated that the nonsense mutation was inherited from the
father and the missense mutation was inherited from the mother.
相似文献