全文获取类型
收费全文 | 8996篇 |
免费 | 645篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 428篇 |
妇产科学 | 168篇 |
基础医学 | 1005篇 |
口腔科学 | 660篇 |
临床医学 | 795篇 |
内科学 | 1536篇 |
皮肤病学 | 109篇 |
神经病学 | 835篇 |
特种医学 | 420篇 |
外国民族医学 | 2篇 |
外科学 | 1500篇 |
综合类 | 105篇 |
一般理论 | 6篇 |
预防医学 | 705篇 |
眼科学 | 232篇 |
药学 | 540篇 |
中国医学 | 2篇 |
肿瘤学 | 560篇 |
出版年
2021年 | 121篇 |
2019年 | 107篇 |
2018年 | 128篇 |
2017年 | 104篇 |
2016年 | 92篇 |
2015年 | 96篇 |
2014年 | 158篇 |
2013年 | 245篇 |
2012年 | 305篇 |
2011年 | 374篇 |
2010年 | 218篇 |
2009年 | 213篇 |
2008年 | 375篇 |
2007年 | 370篇 |
2006年 | 385篇 |
2005年 | 373篇 |
2004年 | 379篇 |
2003年 | 309篇 |
2002年 | 312篇 |
2001年 | 271篇 |
2000年 | 268篇 |
1999年 | 228篇 |
1998年 | 94篇 |
1997年 | 88篇 |
1996年 | 96篇 |
1995年 | 89篇 |
1994年 | 70篇 |
1992年 | 213篇 |
1991年 | 207篇 |
1990年 | 208篇 |
1989年 | 230篇 |
1988年 | 202篇 |
1987年 | 216篇 |
1986年 | 188篇 |
1985年 | 174篇 |
1984年 | 166篇 |
1983年 | 106篇 |
1982年 | 73篇 |
1980年 | 73篇 |
1979年 | 138篇 |
1978年 | 110篇 |
1977年 | 91篇 |
1976年 | 109篇 |
1975年 | 99篇 |
1974年 | 109篇 |
1973年 | 130篇 |
1972年 | 102篇 |
1971年 | 84篇 |
1970年 | 79篇 |
1968年 | 69篇 |
排序方式: 共有9653条查询结果,搜索用时 15 毫秒
61.
62.
M P Mehta J M Rozental A B Levin T R Mackie S S Kubsad M A Gehring T J Kinsella 《International journal of radiation oncology, biology, physics》1992,24(4):619-625
The role of stereotactic radiosurgery in the management of recurrent and newly diagnosed brain metastases was evaluated prospectively. From December 1988 to March 1991, 58 lesions in 40 patients were treated with accelerator-based stereotactic radiosurgery. All patients were followed for a minimum of 6 months or to death. The primary purpose was to determine the impact of radiosurgery on local control and its subsequent effects on quality of life. An overall tumor control rate of 82% with a complete response rate of 43% were achieved. As anticipated, the response rate for smaller tumors was substantially better than that for larger tumors (78% for lesions < 2 cm3; 50% for lesions > or = 10 cm3). Although the overall in-field progression rate was 18.5%, only 1/23 (4%) complete responders subsequently recurred. The in-field failure rate is highly comparable with recently published surgical data. Progression outside the brain was noted in two-thirds of patients. One quarter of the deaths were neurologic. The median survival for this minimally selected patient population was 6.5 months. Stereotactic radiosurgery was also associated with improved quality of life as measured by Karnofsky score, neurologic function, and steroid dependence. Long-term steroid dependence was encountered in only four patients. We conclude that stereotactic radiosurgery can be used effectively in patients with brain metastases. In this series, a high tumor response rate was achieved which was associated with improved quality of life. 相似文献
63.
The Boston AIDS Survival Score (BASS): a multidimensional AIDS severity instrument. 总被引:2,自引:1,他引:1
下载免费PDF全文
![点击此处可从《American journal of public health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
G R Seage rd C Gatsonis J S Weissman J S Haas P D Cleary F J Fowler M P Massagli V E Stone D E Craven H Makadon J Goldberg K Coltin K S Levin A M Epstein 《American journal of public health》1997,87(4):567-573
OBJECTIVES: This study developed a new acquired immunodeficiency syndrome (AIDS) severity system by including diagnostic, physiological, functional, and sociodemographic factors predictive of survival. METHODS: Three-hundred five persons with AIDS in Boston were interviewed; their medical records were reviewed and vital status ascertained. RESULTS: Overall median (+/- SD) survival for the cohort from the first interview until death was 560 +/- 14.4 days. The best model for predicting survival, the Boston AIDS Survival Score, included the Justice score (stage 2 relative hazard [RH] = 1.25, 95% confidence interval [CI] = 0.80, 1.96; stage 3 RH = 1.76, 95% CI = 1.15, 2.70), a newly developed opportunistic disease score (Boston Opportunistic Disease Survival Score; stage 2 RH = 1.35, 95% CI = 0.90, 2.02; stage 3 RH = 2.10, 95% CI = 1.38, 3.18), and measures of activities of daily living (any intermediate limitations, RH = 1.84, 95% CI = 1.05, 3.21; any basic limitations, RH = 2.60, 95% CI = 1.44, 4.69). This model had substantially greater predictive power (R2 = .17, C statistic = .68) than the Justice score alone (R2 = .09, C statistic = .61). CONCLUSIONS: Incorporating data on clinically important events and functional status into a physiologically based system can improve the prediction of survival with AIDS. 相似文献
64.
K Kato A T Lin N Haugaard P A Longhurst A J Wein R M Levin 《The Journal of urology》1990,143(4):844-847
Bladder outlet obstruction has been shown to cause detrusor contractile dysfunction. To determine if alterations in bladder metabolism may in part underlie these functional defects, we investigated the effects of mild outlet obstruction on the glucose metabolism of the rabbit urinary bladder. Mild outlet obstruction was created in mature male rabbits by the surgical placement of a silicon sleeve around the bladder neck. Two weeks after surgery, the in vitro ability of the obstructed bladder tissues to metabolize glucose was compared to that of the controls. The results can be summarized as follows: 1) The bladder wet weight increased 2.3-fold following two weeks of obstruction. 2) Obstructed bladder tissues had a reduced glucose consumption as compared to the controls. 3) CO2 generation was significantly reduced by 31% in obstructed bladder tissues whereas lactate formation increased significantly by 22%. 4) Tissue concentrations of ATP, creatine phosphate, and glycogen before incubation showed no significant differences between control and obstructed bladder tissues. In summary, bladder tissues following two weeks obstruction showed a decrease in aerobic metabolism and an increase in anaerobic metabolism. Previous studies have indicated that the ability of the bladder to maintain a contraction and empty may be directly related to aerobic metabolism. Therefore, the decrease in aerobic metabolism (even in the presence of increased anaerobic metabolism) may in part explain the decreased ability of the obstructed bladder to empty. 相似文献
65.
PURPOSE: To determine if there is an association between the timing of surgical intervention for congenital cataract within the first 12 weeks of life and the prevalence of postoperative complications. METHODS: We performed a retrospective review of records from 1990 to 2000 of infants who underwent surgery for congenital cataract within the first 12 weeks of life. Eighty eyes in 55 children were involved with a minimum follow up of 6 months. Bilateral cataracts were present in 25 and monocular cataracts in 30 infants. A limbal approach lensectomy-vitrectomy was performed in all infants. Children with aphakia were rehabilitated with contact lens or glasses. Operative and postoperative complications-including glaucoma, nystagmus, strabismus, retinal detachment, and posterior capsule opacification/secondary membranes-were recorded. Ocular and systemic associations were noted. Statistical analysis was carried out with classification and regression trees (CART). RESULTS: The mean age at the time of surgery was 31.5 +/- 23.3 days (median, 26.5; range, 2 to 84). Mean follow up from the time of surgery was 2.85 +/-1.9 years (median, 2; range, 0.5 to 8). Persistent fetal vasculature (persistent hyperplastic primary vitreous) was present in 14 eyes. One infant with bilateral persistent fetal vasculature had bilateral retinal dysplasia and was excluded from the analysis. Glaucoma developed in 12 infants (22%); nystagmus was present in 18 infants (33%); strabismus developed in 28 infants (52%); and secondary membranes developed in 7 eyes (13%). CART analysis suggests that glaucoma is more prevalent in infants when the surgery was performed between 13.5 and 43 days of life (CART = 0.370); nystagmus when surgery is performed between 48 and 84 days of life (CART = 0.500); strabismus when surgery is performed between 55.5 and 84 days of life (CART = 0.600); and secondary membranes when surgery is performed between 26.5 and 40 days of life (CART = 0.4). CONCLUSIONS: Our data suggest that the first 2 weeks of life comprise the most favorable time for decreasing postoperative complications resulting from surgical intervention for infants presenting with cataracts within the first 12 weeks of life. 相似文献
66.
67.
A case of uncommon paratesticular mesothelioma in a young patient is presented. Its questionable malignancy, as well as the method of treatment are discussed. 相似文献
68.
69.
70.
Inge Reimann Dimitrios Vittas Steen Levin Nielsen Eiliv Svalastoga 《Acta orthopaedica》1989,60(2):185-187
The resorption pattern of synovial fluid through the lymphatic system from normal and synovitic knee joints in rabbits was studied with 99mHechnetium-rhenium-sulfur colloid injected intraarticularly and monitored for 14 hours with a gamma camera.
On the normal side the regional lymph nodes were visualized after I hour and after 14 hours still 75 percent activity remained in the knee. In the synovitic knees no lymphatic transport could be detected; and the radiotracer was unstable with rapid liberation of technetium, which was excreted in the urine. This radiolysis was not found in vitro in synovitic joint fluid.
The lymphatic transport from normal rabbit knees is low. We found a clear difference in lymphatic transport between normal and synovitic knee joints. 相似文献
On the normal side the regional lymph nodes were visualized after I hour and after 14 hours still 75 percent activity remained in the knee. In the synovitic knees no lymphatic transport could be detected; and the radiotracer was unstable with rapid liberation of technetium, which was excreted in the urine. This radiolysis was not found in vitro in synovitic joint fluid.
The lymphatic transport from normal rabbit knees is low. We found a clear difference in lymphatic transport between normal and synovitic knee joints. 相似文献