全文获取类型
收费全文 | 2631篇 |
免费 | 399篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 80篇 |
妇产科学 | 64篇 |
基础医学 | 441篇 |
口腔科学 | 116篇 |
临床医学 | 271篇 |
内科学 | 531篇 |
皮肤病学 | 57篇 |
神经病学 | 208篇 |
特种医学 | 155篇 |
外科学 | 297篇 |
综合类 | 64篇 |
预防医学 | 349篇 |
眼科学 | 50篇 |
药学 | 226篇 |
中国医学 | 5篇 |
肿瘤学 | 116篇 |
出版年
2021年 | 25篇 |
2019年 | 40篇 |
2018年 | 46篇 |
2017年 | 32篇 |
2016年 | 43篇 |
2015年 | 51篇 |
2014年 | 66篇 |
2013年 | 83篇 |
2012年 | 133篇 |
2011年 | 97篇 |
2010年 | 66篇 |
2009年 | 76篇 |
2008年 | 100篇 |
2007年 | 106篇 |
2006年 | 109篇 |
2005年 | 107篇 |
2004年 | 98篇 |
2003年 | 102篇 |
2002年 | 86篇 |
2001年 | 92篇 |
2000年 | 108篇 |
1999年 | 74篇 |
1998年 | 41篇 |
1997年 | 35篇 |
1996年 | 31篇 |
1995年 | 39篇 |
1994年 | 36篇 |
1993年 | 29篇 |
1992年 | 60篇 |
1991年 | 65篇 |
1990年 | 42篇 |
1989年 | 83篇 |
1988年 | 56篇 |
1987年 | 69篇 |
1986年 | 94篇 |
1985年 | 60篇 |
1984年 | 50篇 |
1983年 | 44篇 |
1982年 | 29篇 |
1981年 | 25篇 |
1980年 | 20篇 |
1979年 | 36篇 |
1978年 | 28篇 |
1977年 | 28篇 |
1976年 | 28篇 |
1973年 | 23篇 |
1972年 | 29篇 |
1971年 | 19篇 |
1970年 | 30篇 |
1968年 | 22篇 |
排序方式: 共有3043条查询结果,搜索用时 328 毫秒
1.
2.
The susceptibilities to ciprofloxacin, DR-3355 (S-(-)-ofloxacin), enoxacin, lomefloxacin, ofloxacin and PD127,391 of 69 significant bacterial isolates from HIV-positive patients at the City Hospital, Edinburgh have been determined. With the exception of the enterococci, most of the strains tested (including staphylococci, Escherichia coli and Pseudomonas aeruginosa) were susceptible to the fluoroquinolones. Ciprofloxacin was the most active of the clinically available drugs followed by ofloxacin, lomefloxacin and enoxacin. PD127,391 and DR-3355, the new fluoroquinolones tested, were at least as active as ciprofloxacin. Hence bacterial infections in AIDS patients should respond to fluoroquinolone therapy. 相似文献
3.
A 32 year old male research physician accidentally received a minor wound from a needle which had been previously used on rabbit tissue. Within 15 minutes serious anaphylactic reactions started and he was taken to hospital where his condition stabilised within five hours. Serum immunoglobulin E antibodies to rabbit epithelium were high (16.2 U/ml), although other antibody titres were low. Allergy tests were not carried out before employment, so this alarming scenario could not have been predicted. People with confirmed laboratory animal allergy should be warned of the dangers of continued unprotected exposure and avoidance of the allergen should be encouraged by good laboratory practice and respiratory protective equipment. 相似文献
4.
The baroreflex maintains blood pressure through the glossopharyngeal (IX) cranial nerve. We report a 54-year-old man who developed a left sided headache, hoarseness, dysarthria, dysphagia, and sustained hypertension from a left internal carotid artery dissection. We hypothesise that interruption of the left IX nerve caused hypertension in this patient. 相似文献
5.
R. C. Small J. P. Boyle K. R. Elliott R. W. Foster A. J. Watt 《British journal of pharmacology》1989,97(4):1174-1181
1. AH 21-132 is being investigated as a potential chemotherapeutic agent for bronchial asthma. The present experiments were designed to determine whether AH 21-132 shares the activity of theophylline as an antagonist at adenosine A1 receptors and to assess its potency as a relaxant in intestinal smooth muscle. 2. In the transmurally-stimulated guinea-pig ileum, theophylline (1 mM), but not AH 21-132 (1 and 10 microM), antagonized twitch depression induced by adenosine. Higher concentrations (100 microM and 1 mM) of AH 21-132 themselves had a depressant effect. Neither theophylline (1 mM) nor AH 21-132 (1 and 10 microM) antagonized twitch depression induced by noradrenaline. 3. AH 21-132 (100 microM and 1 mM) depressed maximum contractions of ileum induced by both acetylcholine (ACh) and histamine. 4. In ileum treated with hyoscine (1 microM), AH 21-132 (greater than 10 microM) caused a concentration-dependent depression of the log concentration-effect curve for potassium chloride. 5. Simultaneous extracellular electrophysiological and mechanical recording from taenia caeci showed that AH 21-132 (100 microM-1 mM) inhibited spontaneous tension waves and their associated bursts of electrical spike activity. 6. Intracellular electrophysiological recording from taenia caeci showed that the mechano-inhibitory effect of 1 mM AH 21-132 was accompanied by abolition of spontaneous spike activity. Following spike abolition, the membrane potential assumed a value very close to that observed during periods of electrical quiescence prior to drug exposure. 7. AH 21-132 inhibited the activity of cyclic AMP-dependent and cyclic GMP-dependent phosphodiesterases derived from homogenates of ileal smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
6.
Post-herpetic neuralgia and topical capsaicin 总被引:5,自引:0,他引:5
Topical 0.025% capsaicin was used to treat 33 patients with post-herpetic neuralgia (PHN). Thirty-nine percent of those entering the trial achieved at least a good result and 55% were improved or better. Fifty-six percent of the 23 patients completing the study had good or excellent pain relief after 4 weeks. Seventy-eight percent of the 23 noted at least some improvement in pain. Post-capsaicin burning was a common, untoward effect in most patients and in about one-third was so unbearable that the trial was terminated prematurely. This treatment appears to be a useful modality in PHN, particularly in the elderly in whom oral medications are often poorly tolerated; however, it does require supervision. A double-blind, controlled trial is now necessary. 相似文献
7.
8.
9.
Oxygen saturation during endoscopic retrograde cholangiopancreatography: a comparison of two protocols of oxygen administration.
下载免费PDF全文
![点击此处可从《Gut》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Patients having endoscopic retrograde cholangiopancreatography (ERCP) are generally elderly and require sedation while in the prone position. These factors may be expected to aggravate any risk of arterial hypoxia. This study evaluated two protocols of oxygen administration, one with and one without pre-oxygenation. In 25 patients in whom pre-oxygenation with 4 litres/minute for five minutes before sedation was used, followed by continuous oxygen administration, arterial oxygen saturation did not fall below 90% at any stage during the procedure. By contrast, in 25 patients who were not pre-oxygenated oxygen saturation fell below 90% in nine (36%). As expected, hypoxia occurred most frequently during the early stages of sedation and endoscope insertion. Hypoxia did not occur in association with operations such as sphincterotomy, stone extraction or stent insertion. This study confirms that arterial hypoxia is a common event during ERCP and can be completely prevented by pre-oxygenation with four litres of oxygen given intranasally for five minutes before sedation. 相似文献
10.
A comparison of the effects of oral nadolol and topical timolol on intraocular pressure, blood pressure, and heart rate. 总被引:1,自引:1,他引:0
下载免费PDF全文
![点击此处可从《The British journal of ophthalmology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
We compared the effects of oral nadolol 20 mg once daily and topical timolol 0.25% twice daily on the intraocular pressures of 22 glaucoma suspects, in a 12 week double-masked crossover study. Both nadolol and timolol reduced intraocular pressure (p less than 0.001). The reductions in intraocular pressure did not differ significantly after two weeks and four weeks of treatment. Nine of these subjects underwent treadmill exercise tests in order to compare the effects of nadolol and timolol on the cardiovascular system. The effects of the two treatments on blood pressure were comparable, but nadolol caused a significantly greater reduction in heart rate than timolol at rest (p less than 0.05). Nadolol reduces intraocular pressure effectively and may prove a useful alternative treatment for chronic simple glaucoma. 相似文献