全文获取类型
收费全文 | 1507篇 |
免费 | 129篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 70篇 |
妇产科学 | 16篇 |
基础医学 | 190篇 |
口腔科学 | 36篇 |
临床医学 | 219篇 |
内科学 | 357篇 |
皮肤病学 | 24篇 |
神经病学 | 26篇 |
特种医学 | 289篇 |
外科学 | 229篇 |
综合类 | 40篇 |
预防医学 | 75篇 |
眼科学 | 16篇 |
药学 | 62篇 |
肿瘤学 | 42篇 |
出版年
2021年 | 18篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 15篇 |
2017年 | 12篇 |
2016年 | 16篇 |
2015年 | 26篇 |
2014年 | 24篇 |
2013年 | 41篇 |
2012年 | 33篇 |
2011年 | 37篇 |
2010年 | 56篇 |
2009年 | 51篇 |
2008年 | 41篇 |
2007年 | 72篇 |
2006年 | 46篇 |
2005年 | 35篇 |
2004年 | 33篇 |
2003年 | 27篇 |
2002年 | 27篇 |
2001年 | 22篇 |
2000年 | 38篇 |
1999年 | 40篇 |
1998年 | 68篇 |
1997年 | 80篇 |
1996年 | 78篇 |
1995年 | 75篇 |
1994年 | 51篇 |
1993年 | 55篇 |
1992年 | 25篇 |
1991年 | 30篇 |
1990年 | 24篇 |
1989年 | 57篇 |
1988年 | 41篇 |
1987年 | 56篇 |
1986年 | 30篇 |
1985年 | 37篇 |
1984年 | 29篇 |
1983年 | 31篇 |
1982年 | 24篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 9篇 |
1978年 | 18篇 |
1977年 | 16篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1973年 | 10篇 |
1969年 | 8篇 |
1966年 | 6篇 |
排序方式: 共有1701条查询结果,搜索用时 31 毫秒
91.
92.
Perkins SN; Hursting SD; Haines DC; James SJ; Miller BJ; Phang JM 《Carcinogenesis》1997,18(5):989-994
Transgenic mice with both alleles of the p53 tumor suppressor gene product
'knocked out' by gene targeting are susceptible to early development of
tumors, chiefly lymphomas and sarcomas. Compared with the control group,
administration of dehydroepiandrosterone (DHEA) at 0.3% of the diet to male
p53-deficient mice extended their lifespan by delaying death due to
neoplasms (from 105 to 166 days on study, P = 0.002), primarily by
suppressing lymphoblastic lymphoma (from 45 to 6% of neoplastic deaths, P =
0.010). Treatment with a synthetic DHEA analog,
16alpha-fluoro-5-androsten-17-one (compound 8354), at 0.15% of the diet
also increased lifespan, to 140 days for mice that developed tumors (P =
0.037). The effects of these steroids on lifespan and tumor development did
not appear to be strongly related to inhibition of food consumption and
weight gain, in that a group pair-fed with control diet to the reduced food
consumption of the DHEA-treated group developed and died of the same types
of neoplasms at the same rate as the controls fed ad libitum. The
chemopreventive effect of these steroids has been proposed to be due to
suppression of DNA synthesis by inhibition of glucose 6-phosphate
dehydrogenase, the rate-limiting enzyme of the pentose phosphate pathway.
Although DHEA and its analog are strong non- competitive inhibitors of this
enzyme in vitro, treatment with DHEA did not deplete cellular nucleotide
pools in the liver, as would have been predicted. The chemopreventive
effect of DHEA in this model may be due to steroid-induced thymic atrophy
and suppression of T cell lymphoma, permitting these mice to survive long
enough to develop tumors with longer latency.
相似文献
93.
94.
Templeton AW; Johnson JA; Anderson WH; Cook LT; Dwyer SJ d; Preston DF; Lee KR; Rosenthal SJ; Batnitzky S; Levine E 《Radiology》1984,151(2):527-528
The increasing use of digitally formatted imaging systems requires high-quality interactive gray-scale computer raster graphics systems for the management, display, and analog film recording of digital image and alphanumeric information. These systems are a combination of computer hardware and software and implement a set of graphics protocols. This paper describes a set of interactive graphics protocols that has been developed for clinical use. 相似文献
95.
Ruptured splenic artery aneurysm in pregnancy. A review. 总被引:1,自引:0,他引:1
96.
In a patient with primary hyperparathyroidism an attempt was made to ablate a middle mediastinal parathyroid gland by forceful staining with radiographic contrast material. The gland was stained on two separate occasions, two weeks apart. Both times the serum calcium level temporarily fell to the normal range but reverted to abnormal levels. The patient ultimately required surgery for correction of hypercalcemia. The mechanism of staining and possible reasons for failure as well as potential complications are discussed. 相似文献
97.
Hyposplenism in inflammatory bowel disease. 总被引:3,自引:3,他引:0
Splenic function was assessed in 35 patients with ulcerative colitis and 20 patients with Crohn's disease. Hyposplenism was diagnosed if there were Howell-Jolly bodies in the peripheral blood film or if there was prolongation of clearance from the peripheral blood of injected 51-Cr-labelled heat-damaged red blood cells. Thirteen of the patients with ulcerative colitis had hyposplenism as compared with only one patient with Crohn's disease. Conversely, heat-damaged red cell clearance values faster than the normal range were found in six out of the 20 patients with Crohn's disease. Four patients with hyposplenism and ulcerative colitis developed life-threatening septicaemia in the early postcolectomy period, two of these being further complicated by disseminated intravascular coagulation. 相似文献
98.
99.
Effect of posture on glucose tolerance after gastric surgery 总被引:1,自引:0,他引:1
100.
Anti-Basement Membrane Antibodies in Immunologic Renal Disease 总被引:2,自引:0,他引:2
Abstract: Anti-basement membrane antibodies are now being associated with an increasing spectrum of disease, including Goodpasture's syndrome, rapidly progressive and occasionally milder forms of glomerulo-nephritis (GN), tubulointerstitial nephritis, pulmonary damage, and potentially other forms of tissue injury. We have developed a radioimmunoassay to detect circulating anti-glomerular basement membrane (GBM) antibodies. The antigens for this assay are derived from the noncollagenous portion of the GBM remaining after collagenase digestion. After immunoabsorptive purification, the major antigens precipitated by human anti-GBM antibodies can be characterized by polyacrylamide gel electrophoresis (PAGE) into an unresolved high molecular weight fraction and two antigenic peaks of 54,000 and 27,000 daltons. The noncollagenous nature of the antigenic material has been confirmed by amino acid analysis. The radiolabelled antigen has proven useful in detecting circulating anti-GBM antibodies in over 500 patients. The assay is of use in monitoring the activity of disease and judging the patient's response to therapy. It is also useful in determining the timing of renal transplantation, if required. Differences in antigenic content of glomerular and tubular basement membranes (TBM) have been noted between individuals. These antigenic differences. under certain circumstances, can lead to the induction of anti-basement membrane antibody responses after transplantation. 相似文献