全文获取类型
收费全文 | 20474篇 |
免费 | 2102篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 665篇 |
妇产科学 | 745篇 |
基础医学 | 3003篇 |
口腔科学 | 551篇 |
临床医学 | 2497篇 |
内科学 | 4087篇 |
皮肤病学 | 298篇 |
神经病学 | 1829篇 |
特种医学 | 684篇 |
外科学 | 2519篇 |
综合类 | 515篇 |
一般理论 | 17篇 |
预防医学 | 2080篇 |
眼科学 | 218篇 |
药学 | 1720篇 |
中国医学 | 32篇 |
肿瘤学 | 1035篇 |
出版年
2021年 | 241篇 |
2020年 | 159篇 |
2019年 | 258篇 |
2018年 | 306篇 |
2017年 | 210篇 |
2016年 | 258篇 |
2015年 | 307篇 |
2014年 | 418篇 |
2013年 | 641篇 |
2012年 | 909篇 |
2011年 | 949篇 |
2010年 | 547篇 |
2009年 | 544篇 |
2008年 | 815篇 |
2007年 | 979篇 |
2006年 | 891篇 |
2005年 | 784篇 |
2004年 | 850篇 |
2003年 | 793篇 |
2002年 | 759篇 |
2001年 | 708篇 |
2000年 | 699篇 |
1999年 | 632篇 |
1998年 | 275篇 |
1997年 | 269篇 |
1996年 | 236篇 |
1995年 | 241篇 |
1994年 | 184篇 |
1993年 | 196篇 |
1992年 | 519篇 |
1991年 | 500篇 |
1990年 | 443篇 |
1989年 | 551篇 |
1988年 | 450篇 |
1987年 | 405篇 |
1986年 | 445篇 |
1985年 | 367篇 |
1984年 | 309篇 |
1983年 | 324篇 |
1982年 | 190篇 |
1981年 | 173篇 |
1980年 | 144篇 |
1979年 | 243篇 |
1978年 | 190篇 |
1977年 | 169篇 |
1976年 | 163篇 |
1974年 | 153篇 |
1973年 | 181篇 |
1972年 | 152篇 |
1971年 | 160篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
32.
33.
Nutritional supplementation, psychosocial stimulation, and growth of stunted children: the Jamaican study 总被引:3,自引:0,他引:3
S P Walker C A Powell S M Grantham-McGregor J H Himes S M Chang 《The American journal of clinical nutrition》1991,54(4):642-648
The benefits of nutritional supplementation, with or without psychosocial stimulation, on the growth of stunted children were evaluated. Children aged 9-24 mo with lengths less than -2 SD of the National Center for Health Statistics references (n = 129) were randomly assigned to four groups: control, nutritional supplementation, stimulation, and both interventions. A fifth group with lengths greater than -1 SD was also enrolled. Length, weight, head and arm circumferences, and triceps and subscapular skinfold thicknesses were measured on enrollment and 6 and 12 mo later. Multiple-regression analysis was used to determine the effects of the interventions in which age, sex, initial status, initial dietary intake, and several socioeconomic variables were controlled for. Stimulation had no effect on growth and there was no interaction between the interventions. After 12 mo supplemented children had significantly increased length, weight, and head circumference (all P less than 0.01). The effects of supplementation were not cumulative but occurred in the first 6 mo. 相似文献
34.
35.
Huang Guo-Shu MD Chang Wei-Chou MD Lee Herng-Sheng MD † Taylor John A. M. DC DACBR ‡ Cheng Tiang-Yeu MD § Chen Cheng-Yu MD 《Dermatologic surgery》2005,31(6):717-719
BACKGROUND: Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin. OBJECTIVE: We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings. METHODS: We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy. RESULTS: Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings. CONCLUSION: Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis. 相似文献
36.
J P Murphy A V Adyanthaya P R Adams J D McArthur W E Walker 《The Annals of thoracic surgery》1987,43(3):323-325
Pulmonary artery aneurysms are rare lesions for which operative management is not frequently undertaken. When operation is indicated, central lesions involving the pulmonary trunk, right main pulmonary artery, or left main pulmonary artery are repaired using cardiopulmonary bypass. Peripheral aneurysms in segmental intrapulmonary arteries have been managed most frequently by lobectomy, but occasionally by aneurysmectomy and pulmonary arterial repair. We used cardiopulmonary bypass for peripheral pulmonary aneurysmectomy in a patient with limited respiratory reserve because he had undergone prior contralateral bilobectomy; this allowed controlled resection while preserving a maximal amount of pulmonary parenchyma. 相似文献
37.
Toxocariasis: a serological survey of blood donors in the Australian Capital Territory together with observations on the risks of infection 总被引:4,自引:0,他引:4
W L Nicholas A C Stewart J C Walker 《Transactions of the Royal Society of Tropical Medicine and Hygiene》1986,80(2):217-221
The sera from 660 healthy blood donors from Canberra were tested for antibodies to Toxocara canis by the ELISA test. The results were compared with those from patients with suspected or confirmed visceral larva migrans or ocular toxocariasis. Over 7% of Canberra sera showed elevated levels of antibody reacting with T. canis antigen. Sera from patients resident in Australia with other helminth parasites did not cross-react with T. canis antigen in our tests. However, studies of sera collected in several tropical countries with other parasitic infection, show that cross-reactions with other parasites are possible. The use of purified glycoprotein antigen does not alter the possibility of cross-reaction. Observations and experiments show that people in Canberra may be exposed to the infective eggs of T. canis. 相似文献
38.
V S Jeganathan S Walker 《European journal of vascular and endovascular surgery》2005,30(3):332-3; author reply 333-4
39.
40.
Conclusions Brain death (or cerebral death) means definitive cessation of all neural functions above the spinal cord, thus implying the irreversible loss of all cerebral and brain stem functions.Spinal cord activity may persist after brain death-priapism, persistence of myotatic reflexes- for a few minutes and this spinal activity may be responsible for coarse limb movements after life-support machines have been turned off.The preservation of these spinal reflexes reinforces the advice to allow only responsible doctors to assist at the declaration of death of the patient. 相似文献