全文获取类型
收费全文 | 1193篇 |
免费 | 65篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 43篇 |
妇产科学 | 24篇 |
基础医学 | 148篇 |
口腔科学 | 18篇 |
临床医学 | 148篇 |
内科学 | 283篇 |
皮肤病学 | 13篇 |
神经病学 | 108篇 |
特种医学 | 141篇 |
外科学 | 97篇 |
综合类 | 18篇 |
一般理论 | 1篇 |
预防医学 | 98篇 |
眼科学 | 30篇 |
药学 | 52篇 |
肿瘤学 | 40篇 |
出版年
2020年 | 7篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2016年 | 9篇 |
2015年 | 13篇 |
2014年 | 24篇 |
2013年 | 26篇 |
2012年 | 40篇 |
2011年 | 38篇 |
2010年 | 39篇 |
2009年 | 32篇 |
2008年 | 42篇 |
2007年 | 60篇 |
2006年 | 53篇 |
2005年 | 38篇 |
2004年 | 32篇 |
2003年 | 35篇 |
2002年 | 32篇 |
2001年 | 28篇 |
2000年 | 32篇 |
1999年 | 38篇 |
1998年 | 41篇 |
1997年 | 34篇 |
1996年 | 22篇 |
1995年 | 19篇 |
1994年 | 22篇 |
1993年 | 16篇 |
1992年 | 31篇 |
1991年 | 20篇 |
1990年 | 25篇 |
1989年 | 33篇 |
1988年 | 35篇 |
1987年 | 46篇 |
1986年 | 23篇 |
1985年 | 36篇 |
1984年 | 17篇 |
1983年 | 12篇 |
1982年 | 13篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 19篇 |
1978年 | 9篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1975年 | 15篇 |
1974年 | 13篇 |
1973年 | 9篇 |
1972年 | 17篇 |
1971年 | 7篇 |
1966年 | 6篇 |
排序方式: 共有1269条查询结果,搜索用时 375 毫秒
1.
Patient history and clinical examination are important for the diagnosis of degenerative joint disease. Here the typical statements of a patient suffering from early osteoarthritis are described and, as far as possible, explained. The joint in question must be systematically examined. Furthermore, the neighboring joints and soft-tissue structures, i.e., muscles, tendons etc., should be examined and evaluated with respect to their importance in hindering the functional chain. The neuroreflectory mechanisms involved herein are described. 相似文献
2.
In this study newly diagnosed male and female lung cancer patients admitted to two Ontario Cancer Foundation treatment clinics were interviewed. Information was obtained on demographic variables, presence of other chronic illness and the following psychosocial attributes: locus of control, social support and personality traits. From the clinic charts, information on stage of disease and pathological diagnosis was obtained. After controlling for the effects of stage and pathological diagnosis, the following psychological variables were found to increase the odds of death from lung cancer among males and females combined at one year after diagnosis: a high need for one aspect of social support, a reserved personality and the extremes of the personality trait soberness vs enthusiasm. 相似文献
3.
Cytoskeletal association of human alpha-interferon-receptor complexes in interferon-sensitive and -resistant lymphoblastoid cells. 总被引:6,自引:2,他引:4
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
L M Pfeffer N Stebbing D B Donner 《Proceedings of the National Academy of Sciences of the United States of America》1987,84(10):3249-3253
Human Daudi lymphoblastoid cells, which are highly sensitive to the antiproliferative action of human leukocyte alpha-interferon (IFN-alpha), and IFN-resistant and IFN-sensitive Daudi subclones (Cl2 and Cl1, respectively), contain 2300 (Kd = 20 X 10(-12) M), 3000 (Kd = 45 X 10(-12) M), and 3700 (Kd = 52 X 10(-12) M) IFN-alpha binding sites per cell, respectively. Thus, these IFN-sensitive and IFN-resistant cells have similar numbers of high-affinity IFN-alpha receptors. IFN-receptor complexes that are insoluble in Triton X-100 accumulate in IFN-sensitive but not in IFN-resistant cells. The ligand-induced accumulation of Triton-insoluble complexes in IFN-sensitive cells was inhibited by cytochalasin B. This suggests that the solubility change of IFN-receptor complexes results from their interaction with the cytoskeletal matrix. The dissociation of IFN-alpha from IFN-sensitive and IFN-resistant cells can be resolved into fast and slow components. IFN-alpha dissociates more slowly from IFN-sensitive cells than from IFN-resistant cells. Very slow dissociation of IFN-alpha from Triton-insoluble complexes correlates with this difference. These observations suggest that IFN-receptor complexes become coupled to the cytoskeletal matrix in IFN-sensitive but not in IFN-resistant cells, and that such interaction is an important element in the mechanism of the antiproliferative action of IFN-alpha on Daudi cells. 相似文献
4.
5.
A methodological review of non-therapeutic intervention trials employing cluster randomization, 1979-1989 总被引:7,自引:0,他引:7
A methodological review is presented of 16 non-therapeutic intervention trials published over the last decade which have randomized intact clusters rather than individuals in treatment groups. Each of the trials was surveyed as to the information supplied on six methodological criteria. Although there is increasing recognition of the methodological issues associated with cluster randomization, many investigators are still not aware of the impact of this design on sample size requirements and analysis considerations. Investigators are urged to publish the cluster-specific event rates observed in their trials as a guide for the planning of future studies. 相似文献
6.
ALBERTO Q FARIAS LUCIANA L GONÇALVES EDUARDO LR CANÇADO ANTONIO C SEGURO SILVIA B CAMPOS CLARICE P ABRANTES-LEMOS FLAIR J CARRILHO 《Journal of gastroenterology and hepatology》2006,20(1):147-152
Background and Aims: Primary biliary cirrhosis (PBC) might be complicated by osteoporosis, whose etiology remains unknown but seems to be multifactorial. Prevalence rates of 30% to 60% for distal renal tubular acidosis (DRTA) have been reported in PBC patients, generally as incomplete DRTA. Although it is undisputed that a reduced bone mineral density (BMD) is the expected outcome among patients who have been suffering from longstanding chronic metabolic acidosis, it is unclear if incomplete DRTA is also associated with metabolic bone disease in PBC patients. The present study was undertaken to compare the BMD of PBC patients with and without DRTA.
Methods: The BMD of 23 PBC patients (11 with DRTA and 12 without), all with normal clearance of creatinine, was assessed by dual energy radiograph absorptiometry. The diagnosis of DRTA was made if the urine pH was above 5.4 in all samples after the oral acid overload, showing tubular inability to acidify urine in the presence of test-induced systemic metabolic acidosis.
Results: Densitometric signs of osteoporosis were found in 82% of DRTA cases and in 83% of patients without DRTA (difference not significant). There were no significant differences in BMD measurement, T and Z scores of patients with and without DRTA.
Conclusions: The present study could not support a correlation between the presence of DRTA and the bone loss observed in PBC patients. 相似文献
Methods: The BMD of 23 PBC patients (11 with DRTA and 12 without), all with normal clearance of creatinine, was assessed by dual energy radiograph absorptiometry. The diagnosis of DRTA was made if the urine pH was above 5.4 in all samples after the oral acid overload, showing tubular inability to acidify urine in the presence of test-induced systemic metabolic acidosis.
Results: Densitometric signs of osteoporosis were found in 82% of DRTA cases and in 83% of patients without DRTA (difference not significant). There were no significant differences in BMD measurement, T and Z scores of patients with and without DRTA.
Conclusions: The present study could not support a correlation between the presence of DRTA and the bone loss observed in PBC patients. 相似文献
7.
F Tannouri F Rypens M O Peny J C Noël C Donner J Struyven F Avni 《Journal of ultrasound in medicine》1998,17(1):63-66
EFE is a rare cardiac disorder with poor prognosis and uncertain cause. Primary and secondary forms have been described. Most authors consider that all EFE is secondary--a reactive process set off in the endocardium by stress on the myocardium. We report two cases representing the primary dilated form and the secondary contracted form. The dilated form was associated with intracavitary thrombus of the left ventricle. In both cases, an unusual presence of subendocardial calcifications was noted. The ultrasonographic findings are discussed. 相似文献
8.
9.
10.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm). 相似文献