全文获取类型
收费全文 | 6551篇 |
免费 | 564篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 337篇 |
妇产科学 | 175篇 |
基础医学 | 837篇 |
口腔科学 | 161篇 |
临床医学 | 468篇 |
内科学 | 1314篇 |
皮肤病学 | 178篇 |
神经病学 | 1027篇 |
特种医学 | 533篇 |
外国民族医学 | 2篇 |
外科学 | 518篇 |
综合类 | 174篇 |
预防医学 | 719篇 |
眼科学 | 50篇 |
药学 | 333篇 |
肿瘤学 | 288篇 |
出版年
2021年 | 69篇 |
2020年 | 60篇 |
2019年 | 73篇 |
2018年 | 86篇 |
2017年 | 65篇 |
2016年 | 80篇 |
2015年 | 99篇 |
2014年 | 120篇 |
2013年 | 172篇 |
2012年 | 288篇 |
2011年 | 269篇 |
2010年 | 173篇 |
2009年 | 142篇 |
2008年 | 273篇 |
2007年 | 293篇 |
2006年 | 255篇 |
2005年 | 243篇 |
2004年 | 253篇 |
2003年 | 233篇 |
2002年 | 214篇 |
2001年 | 190篇 |
2000年 | 172篇 |
1999年 | 159篇 |
1998年 | 102篇 |
1997年 | 95篇 |
1996年 | 84篇 |
1995年 | 84篇 |
1994年 | 56篇 |
1993年 | 88篇 |
1992年 | 179篇 |
1991年 | 156篇 |
1990年 | 145篇 |
1989年 | 167篇 |
1988年 | 173篇 |
1987年 | 174篇 |
1986年 | 141篇 |
1985年 | 125篇 |
1984年 | 111篇 |
1983年 | 92篇 |
1982年 | 68篇 |
1981年 | 71篇 |
1980年 | 66篇 |
1979年 | 96篇 |
1978年 | 50篇 |
1977年 | 77篇 |
1976年 | 64篇 |
1975年 | 53篇 |
1974年 | 65篇 |
1973年 | 70篇 |
1969年 | 52篇 |
排序方式: 共有7146条查询结果,搜索用时 15 毫秒
41.
Mitchel A Kling Salvatore Alesci Gyorgy Csako Rene Costello David A Luckenbaugh Omer Bonne Roman Duncko Wayne C Drevets Husseini K Manji Dennis S Charney Philip W Gold Alexander Neumeister 《Neuropsychopharmacology》2007,62(4):309-313
BACKGROUND: Major depressive disorder (MDD) shows increased coronary artery disease (CAD) risk of unknown mechanism(s). MDD is more common in women than men; CAD diagnosis can be difficult in women. Elevations of the inflammatory markers C-reactive protein (CRP) and serum amyloid A (SAA) predict increased CAD risk in populations; few data on these markers exist in MDD, particularly in remitted patients. METHODS: We measured fasting am serum CRP (high sensitivity, CRP(hs)) and SAA in 18 unmedicated, remitted women with MDD (mean age 41 +/- (SD)12, body mass index (BMI) 25.2 +/- 4.1 kg/m(2)) and 18 BMI-matched healthy control subjects (age 36 +/- 10, BMI 25.3 +/- 3.8 kg/m(2)) on 2 separate occasions, > or = 6 days apart. RESULTS: Repeat SAA and CRP(hs) measurements strongly correlated across study days (SAA: r = .83, p < .001; CRP(hs): r = .94, p < .001). Both SAA (5.30 +/- 3.39 vs. 2.84 +/- 1.87 mg/L, p < .005) and CRP(hs) (3.23 +/- 3.17 vs. 1.12 +/- 1.45 mg/L; p < .01) were significantly elevated in MDD women versus controls. CONCLUSIONS: Elevated SAA and CRP(hs) in remitted, unmedicated women with MDD indicate a pro-inflammatory state unrelated to current depressive symptoms or pharmacotherapy. These findings suggest that inflammatory mechanisms may in part underlie findings of increased CAD risk in MDD. 相似文献
42.
43.
M L McLaws L M Irwig P Mock G Berry J Gold 《The Medical journal of Australia》1988,149(11-12):591-595
In July 1984, the first national Australian Nosocomial Prevalence Survey collected data on 12,742 surgical patients from 265 hospitals. This sample represented 59% of public and private hospitals with 50 or more acute-care beds in Australia. The infection control officers at each hospital provided data on patients in a random sample of beds. The over-all surgical wound infection rate was 4.6%. The surgical wound infection rate was twice (5.4%) as high in public than in private (2.8%) hospitals. The infection rates were greater in larger hospitals in both the public and private sector. However, after adjusting for the other predictor factors that are noted below the infection rate did not show any particular pattern for the size of hospital. Clean surgery had a higher (4.8%) infection rate than did clean-contaminated surgery (2.9%). The infection rate for contaminated surgery was 15.0%. Men were found to have nearly twice (6.5%) the infection rate of women (3.4%). Infection rates were lowest in the 15-to-34 years' age-group and highest in those of over 55 years of age. These trends remained even after adjusting for the other risk factors for infection. The cost of surgical wound infections for all hospitals during the year of 1984 was estimated at approximately $60 million. We suggest that a concerted effort should be made to attempt to reduce the infection rate for clean surgery to 1% or less. 相似文献
44.
Summary In the rat, prolonged administration of the luteinizing, hormone-releasing hormone agonist buserelin (25 μg/kg body wt/day
s.c.) lowers blood estradiol, raises bone resorption, and induces osteopenia. The present study was undertaken to determine
whether withdrawal of buserelin normalizes blood estradiol, slows bone resorption, and corrects buserelin-mediated osteopenia.
Four groups of female rats with45Ca-labeled bones were studied: group 1A received 0.2 ml saline s.c. daily for 4 weeks; group 2A received 0.2 ml buserelin
s.c. daily for 4 weeks; group 1B received 0.2 ml saline s.c. daily for 8 weeks; group 2B received 0.2 ml buserelin s.c. daily
for 4 weeks followed by 0.2 ml saline s.c. daily for 4 weeks. Bone resorption was monitored by measuring urinary45Ca and hydroxyproline. The rats in groups 1A and 2A were killed after 4 weeks and those in groups 1B and 2B after 8 weeks.
The mineral contents of the femoral bones and the whole skeletons were measured. Buserelin lowered blood estradiol, elevated
urinary45Ca and urinary hydroxyproline, and lowered femur and total body calcium and45Ca in group 2A vs. 1A (P<0.05). By contrast all these measurements became similar in groups 2B and 1B. Thus, osteopenia generated by a 4-week period
of buserelin-mediated hypo-estrogenism is reversible by withdrawing buserelin for 4 weeks. Consequently, buserelin administration
and withdrawal may be used to study effects of inducing and reversing estrogen-deficiency bone loss in the rat. 相似文献
45.
46.
47.
This report will discuss the different aspects of long-term steroid therapy. The five major areas of interest are indications for treatment, complications, withdraw, monitoring, and surgical adjustment of dosage. 相似文献
48.
49.
Daily administration of a drug in a distinctive environment establishes contingencies that support Pavlovian conditioning. Environmental cues that are paired with the drug injection and that predict the onset of drug action can become conditioned stimuli. Ultimately, the conditioned stimuli come to predict the availability of drug and develop the potential to engender conditioned drug responses. Various psychostimulant drugs can produce conditioned locotnotion when tested in the presence of environmental cues that were repeatedly associated with the drug experience. The ability of amphetamine and cocaine to produce conditioned locomotion was demonstrated in the present study. Stimulant-like properties of methylenedioxymethamphetamine (MDMA) have been reported in locomotor paradigms, drug discrimination procedures, and human subjective questionnaires. MDMA (5 mg/kg), paired for 5 days to a distinct environment signalled by the presence of a distinct odor, produced enhanced locomotion during a test probe with the odor alone indicating that MDMA can also produce conditioned locomotion. The observation that the stimulus properties of MDMA can also become associated with environmental cues supports the hypothesis that some of the behavioral effects of MDMA resemble those of other classical psychostimulants such as amphetamine and cocaine.This is publication number 5732BCR from the Research Institute of Scripps Clinic 相似文献
50.
Nicholas J Laping Jeffrey I Everitt Kendall S Frazier Mark Burgert Melisa J Portis Caprice Cadacio Leslie I Gold Cheryl L Walker 《Clinical cancer research》2007,13(10):3087-3099
PURPOSE: Transforming growth factor beta (TGF-beta), which generally stimulates the growth of mesenchymally derived cells but inhibits the growth of epithelial cells, has been proposed as a possible target for cancer therapy. However, concerns have been raised that whereas inhibition of TGF-beta signaling could be efficacious for lesions in which TGF-beta promotes tumor development and/or progression, systemic pharmacologic blockade of this signaling pathway could also promote the growth of epithelial lesions. EXPERIMENTAL DESIGN: We examined the effect of a TGF-beta inhibitor on mesenchymal (leiomyoma) and epithelial (renal cell carcinoma) tumors in Eker rats, which are genetically predisposed to develop these tumors with a high frequency. RESULTS: Blockade of TGF-beta signaling with the ALK5/type I TGF-beta R kinase inhibitor, SB-525334, was efficacious for uterine leiomyoma; significantly decreasing tumor incidence and multiplicity, and reducing the size of these mesenchymal tumors. However, SB-525334 was also mitogenic and antiapoptotic for epithelial cells in the kidney and exacerbated the growth of epithelial lesions present in the kidneys of these animals. CONCLUSION: Although pharmacologic inhibition of TGF-beta signaling with SB-525334 may be efficacious for mesenchymal tumors, inhibition of this signaling pathway seems to promote the development of epithelial tumors. 相似文献