全文获取类型
收费全文 | 1365篇 |
免费 | 56篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 74篇 |
妇产科学 | 13篇 |
基础医学 | 180篇 |
口腔科学 | 24篇 |
临床医学 | 225篇 |
内科学 | 311篇 |
皮肤病学 | 37篇 |
神经病学 | 36篇 |
特种医学 | 303篇 |
外国民族医学 | 7篇 |
外科学 | 78篇 |
综合类 | 26篇 |
预防医学 | 44篇 |
眼科学 | 6篇 |
药学 | 75篇 |
肿瘤学 | 61篇 |
出版年
2022年 | 3篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2019年 | 16篇 |
2018年 | 11篇 |
2017年 | 11篇 |
2016年 | 13篇 |
2015年 | 21篇 |
2014年 | 14篇 |
2013年 | 32篇 |
2012年 | 14篇 |
2011年 | 20篇 |
2010年 | 52篇 |
2009年 | 50篇 |
2008年 | 30篇 |
2007年 | 61篇 |
2006年 | 23篇 |
2005年 | 30篇 |
2004年 | 14篇 |
2003年 | 16篇 |
2002年 | 24篇 |
2001年 | 19篇 |
2000年 | 25篇 |
1999年 | 27篇 |
1998年 | 94篇 |
1997年 | 88篇 |
1996年 | 109篇 |
1995年 | 85篇 |
1994年 | 87篇 |
1993年 | 75篇 |
1992年 | 24篇 |
1991年 | 30篇 |
1990年 | 29篇 |
1989年 | 34篇 |
1988年 | 36篇 |
1987年 | 28篇 |
1986年 | 36篇 |
1985年 | 35篇 |
1984年 | 13篇 |
1983年 | 24篇 |
1982年 | 21篇 |
1981年 | 21篇 |
1980年 | 17篇 |
1979年 | 7篇 |
1978年 | 13篇 |
1977年 | 18篇 |
1976年 | 18篇 |
1975年 | 8篇 |
1974年 | 3篇 |
1970年 | 2篇 |
排序方式: 共有1502条查询结果,搜索用时 31 毫秒
111.
112.
The reliability of proton spectroscopic imaging in evaluating fatty infiltration of the liver was investigated in 35 subjects (12 healthy volunteers and 23 patients with fatty livers). With this modified spin-echo technique, fatty liver could be separated from normal liver both visually and quantitatively. On the opposed image, normal liver had an intermediate signal intensity, greater than that of muscle, whereas fatty liver had a lower signal intensity, equal to or less than that of muscle. In normal livers, the lipid signal fraction was less than 10%, while in fatty livers it was greater than 10% and usually exceeded 20%. With this technique, nonuniform fatty infiltration of the liver can be differentiated from hepatic metastases, and the technique may prove useful in the differentiation of some hepatic disorders. 相似文献
113.
114.
Direct demonstration of transsynaptic degeneration in the human visual system: a comparison of retrograde and anterograde changes 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of neurology, neurosurgery, and psychiatry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
RM Beatty AA Sadun LEH Smith JP Vonsattel EP Richardson Jr 《Journal of neurology, neurosurgery, and psychiatry》1982,45(2):143-146
Transneuronal degeneration of retinal ganglion cells was directly demonstrated in a patient who had unilateral removal of the striate cortex forty years prior to necropsy. For comparison, another case is presented showing anterograde transneuronal atrophy forty years after enucleation of one eye. 相似文献
115.
A new technique is described for reversing the direction of the catheter tip during translumbar aortography, without the need for partial withdrawal of the catheter from the aortic lumen. The method ensures optimal delivery of contrast medium at the desired level, while avoiding the risk of retroperitoneal bleeding or dislodgement during catheter manipulation. 相似文献
116.
Five patients with optic neuropathy, four vascular and one demyelinating, are described who each complained of an unusual symptom. Bright flashes of light (phosphenes) occurred in the affected eyes and were evoked by sudden unexpected sounds. Movement of the eye alone did not reproduce the symptom. In all patients the phenomenon was sufficiently prominent to interfere with sleep and was the main complaint of one patient. An anticonvulsant (phenytoin) greatly reduced the frequency and intensity of the phosphene in one patient. 相似文献
117.
Differential CT diagnosis of extruded nucleus pulposus 总被引:1,自引:0,他引:1
118.
McRedmond JP Mulvihill NT Kane M Burke B Aloul B Forde T Walsh M Fitzgerald DJ 《Irish journal of medical science》2004,173(4):204-210
Background Streptokinase resistance may cause suboptimal thrombolytic therapy.
Aim To develop a rapid latex-bead assay to detect streptokinase antibodies.
Methods Sera were obtained from 16 patients presenting with acute myocardial infarction (MI) before treatment with streptokinase
and 1 and 6 months post treatment, and from 100 controls. Sera were assayed for anti-streptokinase antibodies using a functional
streptokinase-neutralising assay.
Results Streptokinase-neutralising activity was low in controls (54±5U/ml) and patients prior to treatment (101±18), increasing to
2,110±823 and 1,017±169 at 1 and 6 months (mean±SEM). The latex assay had a sensitivity of 94% and a specificity of 93% for
detecting individuals with >350U/ml of streptokinase resistance, which is sufficient to neutralise the drug clinically.
Conclusions Estimation of streptokinase resistance using an enzyme immunoassay and a latex bead assay correlated well with serum neutralising
activity. This assay can rapidly identify patients who have a high level of streptokinase-neutralising activity. 相似文献
119.
ChintamaniEmail author Vinay?Singhal JP?Singh Ashima?Lyall Sunita?Saxena Anju?Bansal 《BMC cancer》2004,4(1):48
Background
Neo-adjuvant chemotherapy is an integral part of multi-modality approach in the management of locally advanced breast cancer and it is vital to predict the response in order to tailor the regime for a patient. The common final pathway in the tumor cell death is believed to be apoptosis or programmed cell death and chemotherapeutic drugs like other DNA-damaging agents act on rapidly multiplying cells including both the tumor and the normal cells by following the same common final pathway. This could account for both the toxic effects and the response. Absence or decreased apoptosis has been found to be associated with chemo resistance. The change in expression of apoptotic markers (Bcl-2 and Bax proteins) brought about by various chemotherapeutic regimens is being used to identify drug resistance in the tumor cells. A prospective clinical study was conducted to assess whether chemotherapy induced toxic effects could serve as reliable predictors of apoptosis or response to neo-adjuvant chemotherapy in patients with locally advanced breast cancer. 相似文献120.
In newborns, large amounts of heat are lost from the head, due to its high skin surface area. Insulating the head (for example, with a hat or bonnet) can be a simple and effective method of reducing dry heat loss. In the present study, we evaluated the safety aspects of insulating the head of low-birth-weight naked or clothed newborns by using a heated mannequin that simulates a low-birth-weight newborn. Experimental conditions (comprising a nude and three clothed setups) were performed in a closed incubator at three different air temperatures (29 degrees C, 32 degrees C, and 34 degrees C) and with and without the head being covered with a bonnet in each case, i.e., 24 experimental conditions in all. The study shows that added clothing elements and insulating the head decreases the total heat loss of the mannequin as a whole. As regards the dry heat exchange from the head, wearing a bonnet decreases the local heat loss by an average of 18.9% in all clothed and thermal conditions. This phenomenon could be at the origin of brain overheating in heavily dressed newborns, when unrestricted heat loss is limited to the face only. Our results suggest that--apart from accidental hypothermia-in order to achieve thermal equilibrium of the body, it is preferable to leave the head unprotected and to increase the level of clothing insulation over the rest of the body. 相似文献