全文获取类型
收费全文 | 247092篇 |
免费 | 15241篇 |
国内免费 | 684篇 |
专业分类
耳鼻咽喉 | 3138篇 |
儿科学 | 9081篇 |
妇产科学 | 6169篇 |
基础医学 | 33519篇 |
口腔科学 | 5236篇 |
临床医学 | 21452篇 |
内科学 | 49585篇 |
皮肤病学 | 4893篇 |
神经病学 | 21581篇 |
特种医学 | 9107篇 |
外国民族医学 | 33篇 |
外科学 | 38414篇 |
综合类 | 3534篇 |
现状与发展 | 1篇 |
一般理论 | 197篇 |
预防医学 | 17396篇 |
眼科学 | 6844篇 |
药学 | 17269篇 |
1篇 | |
中国医学 | 604篇 |
肿瘤学 | 14963篇 |
出版年
2022年 | 1391篇 |
2021年 | 3112篇 |
2020年 | 1929篇 |
2019年 | 3203篇 |
2018年 | 3916篇 |
2017年 | 2981篇 |
2016年 | 3600篇 |
2015年 | 4136篇 |
2014年 | 5812篇 |
2013年 | 8266篇 |
2012年 | 12013篇 |
2011年 | 12702篇 |
2010年 | 7209篇 |
2009年 | 6789篇 |
2008年 | 11646篇 |
2007年 | 12437篇 |
2006年 | 12081篇 |
2005年 | 12201篇 |
2004年 | 11687篇 |
2003年 | 10931篇 |
2002年 | 10631篇 |
2001年 | 8406篇 |
2000年 | 8037篇 |
1999年 | 7254篇 |
1998年 | 3174篇 |
1997年 | 2871篇 |
1996年 | 2349篇 |
1995年 | 2216篇 |
1994年 | 1966篇 |
1993年 | 1956篇 |
1992年 | 4591篇 |
1991年 | 4337篇 |
1990年 | 4245篇 |
1989年 | 3964篇 |
1988年 | 3595篇 |
1987年 | 3478篇 |
1986年 | 3348篇 |
1985年 | 3227篇 |
1984年 | 2593篇 |
1983年 | 2192篇 |
1982年 | 1675篇 |
1981年 | 1567篇 |
1980年 | 1343篇 |
1979年 | 2253篇 |
1978年 | 1762篇 |
1977年 | 1499篇 |
1975年 | 1492篇 |
1974年 | 1538篇 |
1973年 | 1525篇 |
1972年 | 1309篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
Paul Little 《The British journal of general practice》2002,52(480):534-535
133.
Martha A. Warpehoski Paul J. Buscemi David C. Osborn Birdwell Finlayson Eugene P. Goldberg 《Calcified tissue international》1981,33(1):211-222
Summary The quantity of protein and carbohydrate comprising the matrix of calcium oxalate monohydrate (COM) renal stones was found
to decrease with distance from the surface of the stone. The average organic concentration of stones 3 to 30 mm in diameter
ranged from 5.7% at the surface to 2.7% at the core. This concentration gradient suggests matrix involvement in a “growth
front” on stone surfaces with migration of organic material from the “older” interior. The matrix distribution was not readily
correlated with density variations or with the presence of hydroxyapatite or calcium oxalate dihydrate. Surface matrix concentrations
were greater than amounts predicted by physical adsorption. Electron microscopy confirmed the presence of the organic-rich
surface layer and also suggested that increase in stone size occurs predominantly by crystal growth with microcrystal aggregates
as growth centers. 相似文献
134.
135.
Paul Steinbok Ken Poskitt D. Douglas Cochrane O. Olof Flodmark 《Child's nervous system》1991,7(1):16-20
Enhanced and non-enhanced computed tomography (CT) brain scans were performed within 72 h of surgery on 21 children in whom brain tumors had been resected totally or subtotally, and scans were repeated at varying intervals thereafter. Biopsies of the resection margins were performed in 12 patients at the end of the surgical procedure. The immediate CT scan showed enhancement in the resection margin in 13 of the 21 patients and in 9 of the 13, the enhancement disappeared on follow-up scans. There was discordance between the results of immediate CT scan examination and the biopsies of the resection margins in 7 of the 12 cases. The advantages and disadvantages of an immediate postoperative scan versus a more delayed CT scan are discussed. 相似文献
136.
137.
The aqueous, organic, and volatile oil extracts of leaves of Eugenia uniflora Linn. Family Myrtaceae were investigated for antibacterial properties using agar dilution techniques. The aqueous extract was the most active against the organisms compared to the organic and volatile oil extracts. The extracts were found to inhibit Gram positive Staphylococcus aureus and Bacillus subtilis and Gram negative Escherichia coli and Shigella dysentcriae. Pseudomonas aeruginosa, Klebsiella pneumoniac, and Salmonella typhi were not inhibited. 相似文献
138.
Recurrence, progression and survival in bladder cancer. A retrospective analysis of 232 patients with greater than or equal to 5-year follow-up 总被引:1,自引:0,他引:1
A retrospective study of 232 bladder tumours with minimum follow-up 5 years is presented. The carcinoma was superficial in 66%, muscle-invasive in 31% and could not be staged in 3%. Primary treatment was mainly transurethral resection for superficial tumour, but was cystectomy or radiotherapy in 22 of 29 T1 G3. Of the superficial tumours, 71% recurred. Progression to higher T stage occurred in 15% of Ta and 29% of T1 tumours, and half of these patients died of bladder cancer. The corrected 5-year survival rates in grades 1, 2A, 2B and 3-4 were 96, 84, 64 and 43%, and in stages Ta, T1, T2 and T3 they were 94, 69, 40 and 31%. All patients with T4 tumour died within 4 years. Among the 45 patients with 40 Gy irradiation + cystectomy, the corrected 5-year survival rate was 83% in superficial and 64% in muscle-invasive tumours, and among the 38 with radical radiotherapy the rates in T1-3 were 46, 36 and 13%. Transurethral resection was successful in most Ta cases. Most T1 tumours were, like T2-4, of higher grade than Ta. Prognosis was worse in T1 than in Ta. After progression to muscle-invasive disease, even during close follow-up the outlook was poor, as poor as for patients with primary muscle-invasive disease. 相似文献
139.
140.
Traumatic infarction of the spinal cord in children 总被引:2,自引:0,他引:2
J U Choi H J Hoffman E B Hendrick R P Humphreys W S Keith 《Journal of neurosurgery》1986,65(5):608-610
Infarction of the spinal cord in childhood is rarely due to trauma. During a 15-year period (1971 to 1985), eight children were admitted to The Hospital for Sick Children, Toronto, with a diagnosis of traumatic infarction of the spinal cord. All of these patients had delayed onset of neurological signs varying between 2 hours and 4 days after their initial trauma. No bone abnormalities were seen on plain spine x-ray films. Myelography was carried out in seven of these children and found to be normal in all seven. Six patients who were paraplegic at the time of admission remained permanently paraplegic, but two with incomplete cord signs did show some improvement. 相似文献