全文获取类型
收费全文 | 718篇 |
免费 | 39篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 32篇 |
妇产科学 | 4篇 |
基础医学 | 63篇 |
口腔科学 | 5篇 |
临床医学 | 84篇 |
内科学 | 135篇 |
皮肤病学 | 7篇 |
神经病学 | 23篇 |
特种医学 | 135篇 |
外科学 | 109篇 |
综合类 | 36篇 |
预防医学 | 72篇 |
眼科学 | 2篇 |
药学 | 35篇 |
中国医学 | 3篇 |
肿瘤学 | 18篇 |
出版年
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 9篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 28篇 |
2010年 | 26篇 |
2009年 | 17篇 |
2008年 | 31篇 |
2007年 | 32篇 |
2006年 | 27篇 |
2005年 | 20篇 |
2004年 | 25篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 14篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 49篇 |
1997年 | 38篇 |
1996年 | 21篇 |
1995年 | 17篇 |
1994年 | 19篇 |
1993年 | 20篇 |
1992年 | 14篇 |
1991年 | 11篇 |
1990年 | 17篇 |
1989年 | 11篇 |
1988年 | 14篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 16篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 7篇 |
1980年 | 12篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1974年 | 4篇 |
1970年 | 7篇 |
1932年 | 4篇 |
1925年 | 2篇 |
1924年 | 2篇 |
排序方式: 共有768条查询结果,搜索用时 15 毫秒
1.
2.
Diseases like rotavirus afflict both upper- and lower-income countries, but most serious illnesses and deaths occur among the latter. It is a vital public health issue that vaccines for these types of global diseases can recover research and development (R&D) costs from high-priced markets quickly so that manufacturers can offer affordable prices to lower-income nations. Cost recovery depends on how high R&D costs are, and this study attempts to replace high, unverified estimates with lower, more verifiable estimates for two new vaccines, RotaTeq (Merck) and Rotarix (GlaxoSmithKline or GSK), based on detailed searches of public information and follow-up interviews with senior informants. We also offer a new perspective on “cost of capital” as a claim for recovery from public bodies. Our estimates suggest that companies can recover all fixed costs quickly from affluent markets and thus can offer these vaccines to lower-income countries at prices they can afford. Better vaccines are a shared project between companies and public health agencies; greater transparency and consistency in reporting of R&D costs is needed so that fair prices can be established. 相似文献
3.
4.
Psychiatrist and consumer attitudes toward the advertising of psychiatric services are examined. The results indicate that consumers are consistently more favorable than psychiatrists toward psychiatric services advertising. Both groups felt that professional magazines are the most appropriate media for psychiatrists who advertise. The psychiatrists reported a higher level of exposure to advertising of psychiatric services than did the consumers. However, some apprehension about psychiatric services advertising also was reported. Managerial implications for advertising usage by the practicing psychiatrist are presented. 相似文献
5.
6.
Brandon JC; Teplick SK; Haskin PH; Sammon JK; Muhr WF; Hofmann AF; Gambescia RA; Zitomer N 《Radiology》1988,166(3):665-667
The authors describe their experience with methyl tertiary butyl ether (MTBE) in a larger series of patients than previously reported in order to acquaint physicians with both its effectiveness for dissolution of common bile duct calculi and the limitations of its use. Ten patients with 13 biliary calculi underwent percutaneous stone dissolution treatment with the experimental cholesterol solvent, MTBE. Three stones completely dissolved within 30 minutes, seven were reduced in size, and three were visibly unaffected. All stones not completely dissolved were easily extracted by means of a stone basket except for one in a patient taken to surgery. Although MTBE perfusion is an effective technique for management of biliary calculi, practitioners should be aware that its use is quite time consuming and its odor difficult to control. 相似文献
7.
Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution. 相似文献
8.
9.
Genotype-phenotype correlation for nucleotide substitutions in the IgII- IgIII linker of FGFR2 总被引:6,自引:3,他引:3
10.
Uroscopy in the 21st century: high-field NMR spectroscopy 总被引:1,自引:1,他引:0
Neild GH; Foxall PJ; Lindon JC; Holmes EC; Nicholson JK 《Nephrology, dialysis, transplantation》1997,12(3):404-417
From the experiments described, it can be seen that there are different
research approaches that can be taken and these are summarized in Table 1.
Whereas much scientific research is principally hypothesis led, there
remains, nevertheless, an important place for exploratory research. High
resolution NMR can measure, directly and simultaneously, a wide range of
endogenous metabolites in biological fluids and has the unique capability
of providing structural information on the metabolites detected. It has
proved to be a powerful research tool with which to study inherited
metabolic diseases, renal disease, drug metabolism, and toxicity, and can
be used to monitor the effects of drug therapy. For instance, by using a
library of experimental toxins one can map the metabolic profile of
site-specific nephron injury. With this approach in man one could
eventually take an unknown disease such as Balkan nephropathy and predict
the initial site of tubular injury, the mode of injury and therefore the
kind of toxin capable of producing that injury. NMR spectroscopic
techniques are still advancing rapidly, with ever increasing sensitivity
and sophistication of NMR pulse sequences to enhance structural elucidation
in complex mixtures. Given the advances in directly coupled HPLC-NMR and
even HPLC-NMR-mass spectroscopy it is likely that these technologies in
conjunction with pattern recognition will make major contribution to our
understanding of renal processes and provide new diagnostic insights in the
21st century.
相似文献