全文获取类型
收费全文 | 1159篇 |
免费 | 71篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 72篇 |
妇产科学 | 11篇 |
基础医学 | 105篇 |
口腔科学 | 31篇 |
临床医学 | 104篇 |
内科学 | 274篇 |
皮肤病学 | 21篇 |
神经病学 | 70篇 |
特种医学 | 244篇 |
外科学 | 66篇 |
综合类 | 59篇 |
预防医学 | 63篇 |
眼科学 | 20篇 |
药学 | 43篇 |
中国医学 | 9篇 |
肿瘤学 | 36篇 |
出版年
2022年 | 1篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 11篇 |
2018年 | 13篇 |
2017年 | 10篇 |
2016年 | 7篇 |
2015年 | 19篇 |
2014年 | 39篇 |
2013年 | 63篇 |
2012年 | 33篇 |
2011年 | 34篇 |
2010年 | 38篇 |
2009年 | 66篇 |
2008年 | 32篇 |
2007年 | 56篇 |
2006年 | 32篇 |
2005年 | 35篇 |
2004年 | 27篇 |
2003年 | 25篇 |
2002年 | 25篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 17篇 |
1998年 | 78篇 |
1997年 | 53篇 |
1996年 | 63篇 |
1995年 | 44篇 |
1994年 | 49篇 |
1993年 | 44篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 11篇 |
1989年 | 39篇 |
1988年 | 27篇 |
1987年 | 25篇 |
1986年 | 19篇 |
1985年 | 12篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 15篇 |
1981年 | 20篇 |
1980年 | 13篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1973年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有1239条查询结果,搜索用时 15 毫秒
91.
Hasegawa BH; Naimuddin S; Dobbins JT d; Mistretta CA; Peppler WW; Hangiandreou NJ; Cusma JT; McDermott JC; Kudva BV; Melbye KM 《Radiology》1986,159(2):537-543
The feasibility of producing patient-specific beam attenuators for chest radiography has been investigated using an anthropomorphic phantom and a human volunteer. A low-dose test exposure is digitized, processed, and used to print a small cerium filter, which is placed in the x-ray beam near the collimator. The final radiograph is recorded on film. The technique results in relatively uniform film exposure, so that structures in all regions of the chest are simultaneously displayed with optimal film contrast. The equalized exposure improves image quality in the normally underpenetrated regions and reduces the role of cross-scatter from the lungs. The image is analogous to optical or computer-processed unsharp masking techniques, but the processing is accomplished in the x-ray beam and results in an improved exposure distribution, giving advantages that cannot be achieved with image processing techniques alone. 相似文献
92.
93.
A normal variant, the foraminal spur, is described in five patients. It was seen on computed tomographic studies as a bony process extending from either the pars or the pedicle into the neuroforamen dorsal to the nerve root. In four of the cases it was seen bilaterally. None of the patients had any symptoms related to these spurs. No associated disease of the neuroforamen or facet was present. These spurs most likely represent ossification of the ligamentum flavum at its point of insertion and should not be mistaken for osteophytes, free disk fragments that have calcified, or fracture fragments. Sagittal reformations are helpful in visualizing the extent of the foraminal spurs. 相似文献
94.
95.
Gerard de Vries Rob AH van Hest Conny CA Burdo Dick van Soolingen Jan H Richardus 《BMC infectious diseases》2009,9(1):151
Background
DNA fingerprinting of Mycobacterium tuberculosis isolates offers better opportunities to study links between tuberculosis (TB) cases and can highlight relevant issues in urban TB control in low-endemic countries. 相似文献96.
97.
Rosebrough SF; Grossman ZD; McAfee JG; Kudryk BJ; Subramanian G; Ritter- Hrncirik CA; Witanowski LS; Tillapaugh-Fay G; Urrutia E 《Radiology》1987,162(2):575-577
Radioimmunoimaging of fresh canine venous thrombi with a murine monoclonal antibody specific for human and dog fibrin has been reported. Successful imaging of canine deep venous thrombi 1, 3, and 5 days old at the time of antibody injection is reported. Images were positive in all dogs, and the uptake of fibrin-specific antibody was equivalent to that of fresh thrombi. 相似文献
98.
ABO compatibility can influence the results of platelet transfusion. Results of a randomized trial 总被引:1,自引:0,他引:1
Sixty consecutive patients with untreated acute leukemia alternately received either ABO-matched or ABO-mismatched random-donor platelet transfusions prepared from pooled platelet concentrate stored for 1 to 3 days. Patients were assigned randomly to receive matched or mismatched platelets as their first transfusion, and the first four transfusions were analyzed. In 40 evaluable patients, there was no significant difference (paired t test) between the 10-minute posttransfusion corrected count increments (CCI) of the initial transfusions of matched and mismatched platelets. In contrast, the second matched transfusion was significantly better than the second mismatched transfusion. This effect of ABO compatibility was particularly pronounced in a subset of patients. Six patients in whom mismatched transfusions were consistently inferior to matched transfusions had either a significant increase in anti-A or -B isoagglutinin titers following the first transfusion or elevated titers before or at the conclusion of the study. Conversely, in five patients in whom there was no apparent effect of ABO mismatching, only one had an increase in isoagglutinin titer. Platelet survival was not altered as the ratio of 18-hour to 10-minute posttransfusion CCl was 0.6 for both matched and mismatched platelet transfusions. These data demonstrate that ABO compatibility can affect the results of random-donor platelet transfusions and that patients who experience poor increments from ABO-mismatched platelets may benefit from a trial of ABO-compatible platelets before the initiation of HLA-matched platelet transfusion. 相似文献
99.
C Neoh FCOphth A Agius-Fernandez FCOphth SB Kaye MD FCOphth EM Molyneux MRCP CA Hart PhD MRCPath 《International journal of clinical practice》1994,48(1):27-28
SUMMARY Four cases of primary meningococcal conjunctivitis in children are reported. This represents an incidence of 2% of patients presenting with conjunctivitis to a paediatric A&E department. All were initially treated with topical chloramphenicol, followed by systemic rifampicin once the diagnosis had been established. No ocular or systemic complications developed, nor recolonisation of the conjunctiva or colonisation of the nasopharynx at follow-up (1–2 years). 相似文献
100.
CA Gateley FRCS WG Lewis FRCS DE Sturdy MS FRCS 《International journal of clinical practice》1993,47(5):276-277
SUMMARY Clinically significant symptoms due to gastrointestinal metastases from primary lung cancers is rare. A case of life-threatening lower gastrointestinal haemorrhage secondary to metastatic squamous cell carcinoma of the lung is reported. Previous reports of such metastases are reviewed, with reference to management and prognosis. After resection of colonic metastases from squamous cell lung cancer, survival is similar to that for primary disease. It is suggested that patients with known or suspected squamous cell lung cancer presenting with lower gastrointestinal symptoms be managed as aggressively as those with no previous history of disease. 相似文献