全文获取类型
收费全文 | 3033篇 |
免费 | 161篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 33篇 |
儿科学 | 81篇 |
妇产科学 | 136篇 |
基础医学 | 304篇 |
口腔科学 | 102篇 |
临床医学 | 233篇 |
内科学 | 512篇 |
皮肤病学 | 42篇 |
神经病学 | 159篇 |
特种医学 | 117篇 |
外科学 | 533篇 |
综合类 | 130篇 |
一般理论 | 3篇 |
预防医学 | 219篇 |
眼科学 | 136篇 |
药学 | 291篇 |
中国医学 | 30篇 |
肿瘤学 | 152篇 |
出版年
2023年 | 32篇 |
2022年 | 73篇 |
2021年 | 116篇 |
2020年 | 59篇 |
2019年 | 105篇 |
2018年 | 138篇 |
2017年 | 70篇 |
2016年 | 85篇 |
2015年 | 98篇 |
2014年 | 130篇 |
2013年 | 145篇 |
2012年 | 255篇 |
2011年 | 276篇 |
2010年 | 155篇 |
2009年 | 112篇 |
2008年 | 175篇 |
2007年 | 185篇 |
2006年 | 150篇 |
2005年 | 129篇 |
2004年 | 111篇 |
2003年 | 120篇 |
2002年 | 83篇 |
2001年 | 45篇 |
2000年 | 40篇 |
1999年 | 37篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 15篇 |
1995年 | 7篇 |
1994年 | 13篇 |
1993年 | 9篇 |
1992年 | 29篇 |
1991年 | 19篇 |
1990年 | 14篇 |
1989年 | 20篇 |
1988年 | 10篇 |
1987年 | 15篇 |
1986年 | 8篇 |
1985年 | 5篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 13篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 7篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1971年 | 5篇 |
排序方式: 共有3213条查询结果,搜索用时 15 毫秒
991.
A. Mahmood N. Agarwal S. Sanyal D. Subrahmanyam 《Basic & clinical pharmacology & toxicology》1978,43(2):99-102
Abstract A considerable increase occurs in D-glucose uptake and brush border sucrase and lactase activities in the intestine of monkeys treated with a single oral dose of DDT. Brush border alkaline phosphatase activity remains unaffected in the pesticide treated animals. In vitro addition of DDT has no effect on the sugar absorption and disaccharidase activities. 相似文献
992.
993.
994.
995.
Madan R Brandwein-Gensler M Schlecht NF Elias K Gorbovitsky E Belbin TJ Mahmood R Breining D Qian H Childs G Locker J Smith R Haigentz M Gunn-Moore F Prystowsky MB 《Head & neck》2006,28(11):1018-1027
BACKGROUND: Members of the ezrin-radixin-moesin (ERM) protein family regulate cellular shape, motility, and proliferation and potentially influence ability to metastasize. We investigated the correlation between ERM subcellular localization and survival in patients with squamous cell carcinoma (SCC) METHODS: Tissue microarrays (TMAs) were constructed from paraffin-embedded tissue. TMA sections were evaluated for ERM protein expression immunohistochemically. The results were compared across clinical and histopathologic variables RESULTS: ERM staining results for 47 patients showed that cytoplasmic ERM expression was prevalent in tumors (>92%). Whereas ezrin and moesin also localized to the membrane, only willin was found in the nucleus of tumors. Multivariable Cox regression analysis demonstrated that strong cytoplasmic ezrin expression was independently associated with poorer survival (p = .04, hazard ratio 1.82) CONCLUSIONS: Both level of expression and subcellular localization of ERM proteins may be important indicators of clinical outcome in SCC. This pilot study justifies the need for an expanded validation study of ERM proteins and clinical outcome. 相似文献
996.
OBJECTIVE: To compare 3 different reduced sampling approaches (truncated area, population and Bayesian; sampling schedule till 48 or 72 hours) with the extensive sampling for the estimation of pharmacokinetic parameters for long half-life drugs in healthy subjects and in patients with renal or hepatic impairment. METHODS: Two drugs (extensively metabolized or extensively excreted) whose half-lives were greater than 30 hours were used in this analysis. Pharmacokinetic parameters such as maximum plasma concentration, clearance and half-life were estimated in healthy subjects and in patients using the above-mentioned 3 reduced sampling approaches and then compared with the extensive sampling. RESULTS: The truncated area method failed to detect the same magnitude of difference in pharmacokinetic parameters between healthy subjects and patient populations that was determined using extensive sampling. On the other hand, the population or Bayesian approach provided the same magnitude of difference in pharmacokinetic parameters between the 2 populations that was observed with extensive sampling. CONCLUSION: This study indicates that the truncated area method may be a less suitable method to accurately characterize the pharmacokinetics of a long half-life drug either in healthy subjects or in patients with renal or hepatic impairment compared to a population or Bayesian approach. 相似文献
997.
Dwivedi AJ Chahin F Agrawal S Patel J Khalid M Lakra Y 《Digestive diseases and sciences》2001,46(5):1013-1015
In summary bezoars are rarely symptomatic. CT scan of the abdomen is rapidly becoming the first tool of diagnosis, while endoscopy still remains the best diagnostic test. Medical treatment is usually successful, as in this case and rarely do patients require surgery. 相似文献
998.
999.
OBJECTIVE: To describe three cases of squamous cell carcinoma of the conjunctiva presenting with corneal and scleral inflammation, thinning, and perforation without any tumor formation. DESIGN: Three case reports. PARTICIPANTS: Three male subjects aged 76, 66, and 61 years. INTERVENTION: The subjects had symptoms of external ocular inflammation with focal corneal or scleral thinning and inflammation, as well as interstitial keratitis in two cases. Initial diagnosis of sclerokeratitis with limbal thinning was made in all three in addition to a pterygium in case 2. MAIN OUTCOME MEASURES: Diagnosis of the carcinoma was delayed for 2 to 24 months in two cases, whereas case 2 was diagnosed on excision of a pterygium from the involved area. RESULTS: All subjects developed intraocular extension after further scleral thinning and perforation without tumefaction. CONCLUSIONS: Squamous cell carcinoma of the conjunctiva may be seen without a distinct mass and can masquerade as sclerokeratitis, scleromalacia, or interstitial keratitis. It seems that diffuse growth with inflammation leads to thinning, necrosis, and perforation of the ocular wall with resultant intraocular spread. Squamous cell carcinoma should be considered in the differential diagnosis of corneal and scleral thinning, perforation, and inflammation of unknown cause, especially in the older male subject. 相似文献
1000.
Different optical imaging technologies have significantly progressed over the last years. Besides advances in imaging techniques and image reconstruction, new "smart" optical contrast agents have been developed which can be used to detect molecular targets (such as endogenous enzymes) in vivo. The combination of novel imaging technologies coupled with smart agents bears great diagnostic potential both clinically and experimentally. This overview outlines the basic principles of optical imaging and summarizes the current state of the art. 相似文献