全文获取类型
收费全文 | 6171篇 |
免费 | 560篇 |
国内免费 | 41篇 |
专业分类
耳鼻咽喉 | 47篇 |
儿科学 | 114篇 |
妇产科学 | 301篇 |
基础医学 | 729篇 |
口腔科学 | 136篇 |
临床医学 | 713篇 |
内科学 | 1359篇 |
皮肤病学 | 73篇 |
神经病学 | 611篇 |
特种医学 | 328篇 |
外科学 | 696篇 |
综合类 | 131篇 |
一般理论 | 2篇 |
预防医学 | 362篇 |
眼科学 | 167篇 |
药学 | 355篇 |
中国医学 | 63篇 |
肿瘤学 | 585篇 |
出版年
2023年 | 37篇 |
2022年 | 69篇 |
2021年 | 140篇 |
2020年 | 82篇 |
2019年 | 182篇 |
2018年 | 203篇 |
2017年 | 166篇 |
2016年 | 187篇 |
2015年 | 234篇 |
2014年 | 272篇 |
2013年 | 334篇 |
2012年 | 446篇 |
2011年 | 470篇 |
2010年 | 297篇 |
2009年 | 285篇 |
2008年 | 339篇 |
2007年 | 306篇 |
2006年 | 360篇 |
2005年 | 266篇 |
2004年 | 269篇 |
2003年 | 238篇 |
2002年 | 205篇 |
2001年 | 156篇 |
2000年 | 143篇 |
1999年 | 119篇 |
1998年 | 52篇 |
1997年 | 50篇 |
1996年 | 39篇 |
1995年 | 21篇 |
1994年 | 26篇 |
1993年 | 27篇 |
1992年 | 73篇 |
1991年 | 74篇 |
1990年 | 58篇 |
1989年 | 63篇 |
1988年 | 38篇 |
1987年 | 38篇 |
1986年 | 48篇 |
1985年 | 35篇 |
1984年 | 30篇 |
1983年 | 33篇 |
1982年 | 24篇 |
1981年 | 22篇 |
1979年 | 20篇 |
1978年 | 19篇 |
1977年 | 16篇 |
1975年 | 14篇 |
1974年 | 30篇 |
1973年 | 21篇 |
1972年 | 18篇 |
排序方式: 共有6772条查询结果,搜索用时 15 毫秒
1.
2.
3.
Nonsurgical management of partial adhesive small-bowel obstruction with oral therapy: a randomized controlled trial 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Canadian Medical Association journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
4.
Feng-Yuan Liu Chien-Yu Lin Joseph T Chang Shu-Hang Ng Shy-Chyi Chin Hung-Ming Wang Chun-Ta Liao Sheng-Chieh Chan Tzu-Chen Yen 《Journal of nuclear medicine》2007,48(10):1614-1619
Conventional work-up (CWU) with chest radiography, abdominal ultrasonography, and skeletal scintigraphy has limited value in M staging of nonkeratinizing nasopharyngeal carcinoma (NPC). Our aim was to evaluate whether (18)F-FDG PET could replace CWU by comparing their diagnostic efficacies. METHODS: Patients with histologically proven nonkeratinizing NPC and no prior treatment were prospectively enrolled. All study participants underwent CWU and (18)F-FDG PET for primary M staging. Distant metastasis was considered to be present if there was any reliable evidence identified within 1 y after diagnosis. The comparative diagnostic efficacies of (18)F-FDG PET, CWU, and the combination of (18)F-FDG PET and CWU (PET+CWU) were evaluated using the areas under the receiver-operating-characteristic (ROC) curves. RESULTS: Sixty-one (20.3%) of 300 eligible patients were found to have distant metastases. On a patient-based analysis, (18)F-FDG PET was found to be more effective than CWU (P < 0.001), whereas it was equally effective with PET+CWU (P = 0.130). On region-based analyses, (18)F-FDG PET was more effective than skeletal scintigraphy and chest radiography for detecting bone metastases (P < 0.001) and chest metastases (P < 0.001), respectively. (18)F-FDG PET and abdominal ultrasound were equally effective for detecting hepatic metastases (P = 0.127). On region-based analyses, the combination of (18)F-FDG PET and CWU did not yield any noticeable increase in diagnostic efficacy. CONCLUSION: (18)F-FDG PET can replace CWU in primary M staging of nonkeratinizing NPC. 相似文献
5.
6.
7.
8.
Because of concern about psoralen-induced phototoxicity and photocarcinogenesis, we investigated the effects of dietary lipids in a mouse model in which 8-methoxypsoralen (8-MOP) and UVA (PUVA) therapy has been shown to be carcinogenic. SKH-Hr-1 hairless albino mice were fed diets containing either omega-3 or omega-6 fatty-acid sources (menhaden oil and corn oil, respectively). After 2 weeks on the diets, the mice were treated topically with 8-MOP and then exposed to UVA (5 J/cm2). Mice receiving the omega-3 fatty-acid source exhibited a marked decrease in inflammatory response and a more rapid repair, as expressed both grossly and microscopically. In support of the latter response, i.e. repair, ornithine decarboxylase activity was about 20% greater in animals receiving the omega-3 fatty-acid source. The effects of the dietary fatty acid sources on PUVA tumorigenesis were examined in long-term studies in which animals were treated topically with 0.01% 8-MOP thrice weekly after which they were exposed to UVA (1 J/cm2). These studies indicated that a dietary lipid rich in omega-3 fatty acid and known to exhibit anti-inflammatory properties can markedly ameliorate the course of PUVA toxicity but does not impede the course of PUVA tumorigenesis 相似文献
9.
C Y Chai W C Wu S Wang C K Su Y F Lin C T Yen J S Kuo M J Wayner 《Brain research bulletin》1992,29(1):15-26
The effects of electrical stimulation and microinjection of sodium glutamate (0.5 M) in the sympathetic pressor areas of the dorsal medulla (DM), ventrolateral medulla (VLM), and parvocellular nucleus (PVC) on the knee jerk, crossed extension, and evoked potential of the L5 ventral root produced by intermittent electrical stimulation were studied in 98 adult cats anesthetized with chloralose and urethane. During electrical and glutamate stimulation of these pressor areas, in addition to the rise of systemic arterial blood pressure marked inhibition of the spinal reflex was produced, indicating presence of neuronal perikarya responsible for these actions. Mild to moderate augmentation of spinal reflexes was also observed during brain stimulation but only in a few cases. The magnitude of the somatic effects among the pressor areas of the VLM, DM, and PVC subsequent to glutamate activation was about the same. Induced spinal reflex inhibition, independent from the baroreceptor and vagal influence, remained essentially unaltered after acute midcollicular decerebration. The inhibition was also observed in cats decerebellated 8-10 days in advance. The inhibition was not affected after bilateral electrolytic- or kainic-acid-induced lesions in the paramedian reticular nucleus (PRN). On the contrary, PRN-induced spinal reflex inhibition was attenuated after bilateral lesions in the DM or VLM. Data suggest that there coexists neuronal subpopulations in the VLM, DM, and PVC that can affect both the sympathetic pressor systems and spinal reflexes. 相似文献
10.