全文获取类型
收费全文 | 1355篇 |
免费 | 88篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 38篇 |
妇产科学 | 20篇 |
基础医学 | 173篇 |
口腔科学 | 58篇 |
临床医学 | 191篇 |
内科学 | 306篇 |
皮肤病学 | 6篇 |
神经病学 | 73篇 |
特种医学 | 207篇 |
外科学 | 90篇 |
综合类 | 33篇 |
一般理论 | 1篇 |
预防医学 | 83篇 |
眼科学 | 5篇 |
药学 | 109篇 |
肿瘤学 | 58篇 |
出版年
2023年 | 8篇 |
2022年 | 5篇 |
2021年 | 22篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 19篇 |
2017年 | 11篇 |
2016年 | 16篇 |
2015年 | 16篇 |
2014年 | 27篇 |
2013年 | 40篇 |
2012年 | 42篇 |
2011年 | 48篇 |
2010年 | 53篇 |
2009年 | 75篇 |
2008年 | 53篇 |
2007年 | 54篇 |
2006年 | 42篇 |
2005年 | 57篇 |
2004年 | 44篇 |
2003年 | 49篇 |
2002年 | 34篇 |
2001年 | 33篇 |
2000年 | 38篇 |
1999年 | 31篇 |
1998年 | 52篇 |
1997年 | 49篇 |
1996年 | 52篇 |
1995年 | 48篇 |
1994年 | 34篇 |
1993年 | 33篇 |
1992年 | 18篇 |
1991年 | 20篇 |
1990年 | 15篇 |
1989年 | 33篇 |
1988年 | 46篇 |
1987年 | 25篇 |
1986年 | 18篇 |
1985年 | 22篇 |
1984年 | 14篇 |
1983年 | 13篇 |
1982年 | 21篇 |
1981年 | 12篇 |
1980年 | 20篇 |
1979年 | 13篇 |
1978年 | 15篇 |
1977年 | 12篇 |
1976年 | 10篇 |
1975年 | 10篇 |
1973年 | 5篇 |
排序方式: 共有1463条查询结果,搜索用时 15 毫秒
1.
2.
Coronary artery bypass grafts: visualization with MR imaging 总被引:1,自引:0,他引:1
3.
Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence. 相似文献
4.
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
5.
表小檗碱对α受体的作用 总被引:2,自引:0,他引:2
表小檗碱(epiberberine,EB)是从湖北产黄连(Coptis chinensis Franch)中提取的一种生物碱,属苯喹嗪类原小檗碱,对其药理作用的研究资料甚少,未见其对α肾上腺素体作用的报道。资料表明,许多原小檗碱类化合物有α受体阻滞作用,为从该类化合物中选择 相似文献
6.
A survey of the current methods used in the UK to assess pituitary function. 总被引:1,自引:0,他引:1 下载免费PDF全文
A national survey of the current methods used by specialists to evaluate pituitary function in the UK was performed by postal questionnaire. Seventy-three respondents, of whom 89% were consultants and 80% clinical endocrinologists, returned the questionnaire. Fifty per cent routinely used the insulin stress test (IST) to evaluate the hypothalamo-pituitary-adrenal (HPA) axis, while 50% routinely used tetracosactrin stimulation, there being little overlap between the two groups. This represents a significant change in clinical practice since the last survey in 1988. In those who used ACTH stimulation there was almost an equal split into those who administered the tetracosactrin intramuscularly (45%) or intravenously (47%). Furthermore, either the peak or 60 min cortisol value was used by 71% when interpreting the result of the test, despite the fact that in previous studies only the 30 min cortisol value has been shown to correlate with the IST result. The IST remains the most frequently used method to assess growth hormone reserve in adult subjects. The thyrotrophin-releasing-hormone and gonadotrophin-releasing-hormone tests are still used routinely by approximately a quarter of clinicians. These results provide data that could be used to develop guide-lines for the use of tests to investigate pituitary function. 相似文献
7.
The purpose of this pilot study was to observe both relaxed and deep breathing patterns in a convenience sample to determine the incidence of normal versus faulty patterns of respiration. These observations were then combined with respondent answers to a survey on pain history to determine if there is any correlation between faulty breathing and musculo-skeletal pain patterns. If such a correlation can be made, then we propose that clinicians working with chronic pain patients may have improved outcomes if they address and correct faulty breathing patterns. Based on this study, it is suggested to include the evaluation and treatment of faulty respiration in the rehabilitation of chronic musculo-skeletal conditions, most notably cervical pain. 相似文献
8.
The use of glutamate antagonists and GABA agonists may protect neurons from the effects of transient ischemia. Felbamate is a new antiepileptic drug with glutamate antagonist and GABA agonist properties, We tested the efficacy of felbamate in a gerbil model of transient forebrain ischemia. Damage assessment was done with silver staining at 7 and 28 days after 5 min of bilateral carotid occlusion, Cerebral cortex, hippocampus (CA1 and CA4), thalamus and striatum were evaluated on a 4-point scoring system, The animals sacrificed at 28 days were also tested in a water-maze task to assess recovery of function, The initial dose of felbamate (300 mg/kg) was given 30 min before the ischemic insult in one set of animals and 30 min after the insult in another set of animals. There were 8 animals tested per group (total: 48 animals). There was significant neuronal protection with the use of felbamate, both before and after ischemia in all regions of the brain. Protection was seen in animals sacrificed at 7 and 28 days, Protection was moderate when felbamate was used before ischemia. It was highly significant when felbamate was given 30 min after the insult. Behavioral studies however did not show any difference in the felbamate treated animals versus the saline treated controls. The structural protection with felbamate was very significant when used in the post-ischemic period. This window for protection merits further evaluation in relation to the clinical setting of stroke. 相似文献
9.
Y. W. Loke A. King T. Burrows L. Gardner M. Bowen S. Hiby S. Howlett N. Holmes D. Jacobs 《Tissue antigens》1997,50(2):135-146
A monoclonal antibody to HLA-G has been generated by immunizing HLA-A2.1/human β2 -microglobulin (β2 m) double transgenic mice with murine L cells transfected with both human β2 m and HLA-G. This monoclonal antibody, designated as G233, has been found not to cross-react with other HLA class I antigens when tested on numerous cell lines by flow cytometry. With immunohistology, all populations of extravillous trophoblast (cell columns, interstitial trophoblast, endovascular trophoblast, placental bed giant cells) were stained. An extensive range of adult and fetal tissues was also tested but none reacted with monoclonal antibody G233, including those previously reported to express HLA-G mRNA, indicating that the protein has a highly restricted distribution. Failure to detect HLA-G in the fetal thymus raises the question as to how T-cell tolerance to this antigen is induced. Immunoprecipitation of trophoblast surface proteins with monoclonal antibody G233 revealed a heavy chain of 39 kDa and a light chain of 12 kDa, indicating that HLA-G expressed on the surface of trophoblast is complexed with p2m. However, sequential immunoprecipitation with monoclonal antibody W6/32 followed by monoclonal antibody G233 continued to detect a residual band of 39 kDa, suggesting that trophoblast surface HLA-G may also occur as free heavy chains not associated with p2m. Immunoprecipitation followed by two dimensional gel electrophoresis showed that monoclonal antibody G233 recognizes several iso-forms of HLA-G from trophoblast similar to the characteristic spot array previously described for HLA-G. This monoclonal antibody G233 will be highly useful in future experiments to elucidate the function of HLA-G. 相似文献
10.