全文获取类型
收费全文 | 7784篇 |
免费 | 825篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 211篇 |
妇产科学 | 102篇 |
基础医学 | 1162篇 |
口腔科学 | 145篇 |
临床医学 | 1014篇 |
内科学 | 1444篇 |
皮肤病学 | 137篇 |
神经病学 | 733篇 |
特种医学 | 210篇 |
外科学 | 1163篇 |
综合类 | 222篇 |
一般理论 | 7篇 |
预防医学 | 1118篇 |
眼科学 | 108篇 |
药学 | 416篇 |
1篇 | |
中国医学 | 8篇 |
肿瘤学 | 335篇 |
出版年
2021年 | 112篇 |
2020年 | 59篇 |
2019年 | 117篇 |
2018年 | 109篇 |
2017年 | 110篇 |
2016年 | 84篇 |
2015年 | 111篇 |
2014年 | 126篇 |
2013年 | 249篇 |
2012年 | 329篇 |
2011年 | 356篇 |
2010年 | 205篇 |
2009年 | 189篇 |
2008年 | 346篇 |
2007年 | 301篇 |
2006年 | 328篇 |
2005年 | 315篇 |
2004年 | 297篇 |
2003年 | 247篇 |
2002年 | 281篇 |
2001年 | 271篇 |
2000年 | 271篇 |
1999年 | 236篇 |
1998年 | 98篇 |
1997年 | 87篇 |
1996年 | 61篇 |
1995年 | 59篇 |
1993年 | 69篇 |
1992年 | 191篇 |
1991年 | 182篇 |
1990年 | 191篇 |
1989年 | 173篇 |
1988年 | 167篇 |
1987年 | 159篇 |
1986年 | 162篇 |
1985年 | 164篇 |
1984年 | 121篇 |
1983年 | 108篇 |
1982年 | 84篇 |
1981年 | 81篇 |
1980年 | 72篇 |
1979年 | 76篇 |
1978年 | 85篇 |
1977年 | 58篇 |
1976年 | 62篇 |
1974年 | 74篇 |
1973年 | 59篇 |
1972年 | 58篇 |
1971年 | 68篇 |
1970年 | 57篇 |
排序方式: 共有8616条查询结果,搜索用时 4 毫秒
21.
22.
M B Patterson J L Mack M M Neundorfer R J Martin K A Smyth P J Whitehouse 《Alzheimer disease and associated disorders》1992,6(3):145-163
Assessment of activities of daily living (ADL) in Alzheimer disease (AD) is critical in establishing the diagnosis, monitoring disease progression, evaluating the efficacy of treatment interventions, and determining the need for health and social services. The proper method to measure ADL depends on the purposes to which the scale is to be put. Existing ADL scales differ as to the type of behaviors assessed, the nature of the observations made, and the manner in which the observations are quantified. These scales were not specifically designed to evaluate changes in the nature and extent of the broad spectrum of functional difficulties seen in individuals with AD. We describe the Cleveland Scale for Activities of Daily Living (CSADL), an informant-based instrument designed to expand upon the capacity of existing physical and instrumental ADL scales by assessing both premorbid and current component acts (e.g., initiation versus implementation) of daily living functions. 相似文献
23.
Previous reports in the literature have described correlation of increasing repeat length with severity of the phenotype, in Kennedy syndrome. We describe male siblings with different repeat lengths, with lack of expression of the phenotype in the sibling with the longer repeat length. The phenotype was identical to motor neurone disease. There is variability of expression in Kennedy syndrome and repeat length even in siblings cannot be taken as a conclusive indicator of severity. CAG repeat length cannot be used to predict the natural history of Kennedy disease. The diagnosis of Kennedy syndrome should be considered in male patients presenting with atypical motor neurone disease. 相似文献
24.
W. J. Patterson D. V. Seal E. Curran T. M. Sinclair J. C. McLuckie 《Epidemiology and infection》1994,112(3):513-525
The investigation, epidemiology, and effectiveness of control procedures during an outbreak of Legionnaires'' disease involving three immunosuppressed patients are described. The source of infection appeared to be a network of fire hydrant spurs connected directly to the incoming hospital mains water supply. Removal of these hydrants considerably reduced, but failed to eliminate, contamination of water storage facilities. As an emergency control procedure the incoming mains water was chlorinated continuously. Additional modifications to improve temperature regulation and reduce stagnation also failed to eliminate the legionellae. A perspex test-rig was constructed to model the pre-existing hospital water supply and storage system. This showed that through the hydraulic mechanism known as ''temperature buoyancy'', contaminated water could be efficiently and quickly exchanged between a stagnant spur pipe and its mains supply. Contamination of hospital storage tanks from such sources has not previously been considered a risk factor for Legionnaires'' disease. We recommend that hospital water storage tanks are supplied by a dedicated mains pipe without spurs. 相似文献
25.
The present study is a quantitative analysis of the unmyelinated fiber population in the fasciculus gracilis of the second cervical segment of cat and monkey. We find that unmyelinated fibers represent 13.7% of the total fiber population in this pathway in the cat and 18.9% in the monkey (Macaca fascicularis). The existence of such large numbers of these axons suggests that there may be a sizeable ascending fine primary afferent pathway in the fasciculus gracilis in cat and monkey whose destination is presumably the dorsal column nuclei. These findings are of interest in regard to classic ideas that the afferent fibers in the dorsal columns are large myelinated fibers that convey fine discriminative information to the dorsal column nuclei. 相似文献
26.
27.
Renal toxicities of chemotherapy. 总被引:1,自引:0,他引:1
28.
Firearms in the home and child safety 总被引:3,自引:0,他引:3
One hundred fifty families who were seen in the pediatric outpatient clinics at The University of Texas Medical Branch, Galveston, were surveyed to learn about firearm possession in the home and its hazards to children. Thirty-eight percent of these families kept at least one gun in their home. Fifty-five percent of this group reported that the gun was loaded at all times, and 10% reported that the gun was kept loaded, unlocked, and within the reach of a child. We identified demographic characteristics of at-risk families and considered national statistics for gun safety. It was concluded that household firearms pose a significant risk to children and that intervention by physicians could help reduce this public health problem. 相似文献
29.
Vein patch versus primary closure for carotid endarterectomy. A randomized prospective study in a selected group of patients 总被引:2,自引:0,他引:2
G P Clagett C B Patterson D F Fisher R E Fry J F Eidt T H Humble W J Fry 《Journal of vascular surgery》1989,9(2):213-223
During a 4-year period, 136 patients undergoing 152 carotid endarterectomies consented to be randomized to primary or saphenous vein patch closure of the arteriotomy. At operation, before randomization, careful assessment of arterial dimensions and anatomy was made. Patients who had an internal carotid artery (ICA) diameter less than 5 mm, arteriotomy extending more than 3 cm beyond the origin of the ICA, or tortuous or kinked ICAs were not randomized; they received obligatory vein patch closure (necessary in 20% cases). All patients were followed up every 3 months for 1 year and every 6 months thereafter with duplex scanning, ocular pneumoplethysmography, and neurologic assessment. The incidence of atherosclerotic risk factors was equal in the groups and all except one of the patients were male. Perioperative morbidity was not significantly different among those having primary closure (n = 60), saphenous vein patch closure (n = 62), and obligatory vein patch closure (n = 30). Operative time among patients having primary closure (122 +/- 4 minutes) was significantly less (p less than 0.001) than among those having saphenous vein patch closure (150 +/- 3 minutes). Three perioperative strokes were evenly distributed among the groups (2% for all procedures); no deaths and no acute postoperative occlusions occurred. Recurrent disease occurred in 12.9% of patients having saphenous vein patch closure compared with its occurrence in 1.7% of those having primary closure (p less than 0.05). However, most recurrences were moderate stenoses (25% to 50% diameter reduction), all were smooth-surfaced, and none required a second operation. All except one of the recurrences among those patients with saphenous vein patch closure were in the bulb and the origin of the ICA; two had evidence of regression. This finding suggested that thrombus layering in the dilated part of the saphenous vein patch reconstruction was the cause. This study demonstrates that in men with carotid arteries of predetermined minimal dimensions undergoing carotid endarterectomy routine saphenous vein patch closure does not produce superior results, is associated with a higher incidence of early recurrence, and increases operative time. In selected patients with anatomic risk factors for recurrent disease or acute postoperative occlusion, saphenous vein patch closure is appropriate. 相似文献
30.
The urinary tract undergoes profound physiologic and anatomic changes during pregnancy that facilitate the development of symptomatic urinary tract infections in women with bacteriuria. While the adverse effects of asymptomatic bacteriuria on maternal and fetal health continue to be debated, it is clear that asymptomatic bacteriuria is the major risk factor for developing symptomatic urinary tract infection and that symptomatic infections are associated with significant maternal and fetal risks. Because the majority of symptomatic urinary tract infections develop in women with bacteriuria earlier in pregnancy, treatment of bacteriuria is undertaken to prevent symptomatic infections. All women should be screened at the first antenatal visit, which is reliably and inexpensively done with a dipstick culture. Short-course therapy is as effective as prolonged therapy and should be followed with a repeat culture to document clearing of the bacteriuria. Failure to eliminate bacteriuria with repeated therapy or recurrence with the same organism is indicative of renal parenchymal infection or a structural abnormality. All women with persistent bacteriuria or recurrent infection should have follow-up cultures and a complete urologic evaluation after delivery. 相似文献