全文获取类型
收费全文 | 651篇 |
免费 | 35篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 37篇 |
妇产科学 | 4篇 |
基础医学 | 57篇 |
口腔科学 | 20篇 |
临床医学 | 46篇 |
内科学 | 168篇 |
皮肤病学 | 8篇 |
神经病学 | 31篇 |
特种医学 | 82篇 |
外科学 | 70篇 |
综合类 | 64篇 |
预防医学 | 28篇 |
眼科学 | 16篇 |
药学 | 28篇 |
肿瘤学 | 33篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 10篇 |
2016年 | 11篇 |
2015年 | 16篇 |
2014年 | 14篇 |
2013年 | 22篇 |
2012年 | 14篇 |
2011年 | 19篇 |
2010年 | 26篇 |
2009年 | 35篇 |
2008年 | 17篇 |
2007年 | 26篇 |
2006年 | 39篇 |
2005年 | 14篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 14篇 |
2001年 | 13篇 |
2000年 | 11篇 |
1999年 | 16篇 |
1998年 | 44篇 |
1997年 | 31篇 |
1996年 | 41篇 |
1995年 | 21篇 |
1994年 | 18篇 |
1993年 | 24篇 |
1992年 | 8篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 12篇 |
1988年 | 27篇 |
1987年 | 10篇 |
1986年 | 10篇 |
1985年 | 17篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1969年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有693条查询结果,搜索用时 15 毫秒
51.
Priyadarshini Arunakumar DM Anoop Ayyappan MD Deepa Sasikumar DM KM Krishnamoorthy DM 《Echocardiography (Mount Kisco, N.Y.)》2018,35(5):733-734
A 12‐year‐old child presented with recurrent respiratory infections and was diagnosed with Scimitar syndrome. Drainage of IVC and course of aberrant arterial supply from aorta were not clear by echocardiogram, and hence, additional imaging was planned. CT unraveled the presence of a rare combination of anomalous pulmonary venous connection (APVC) to IVC, with near‐atresia/severe stenosis of IVC, superior to the drainage of scimitar vein. There was a prominent azygos vein with preferential contrast opacification on lower limb injection. 相似文献
52.
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
53.
Mewissen MW; Erickson SJ; Foley WD; Lipchik EO; Olson DL; McCann KM; Schreiber ER 《Radiology》1989,173(1):155-157
Color Doppler flow imaging or compression ultrasound (US) was used to prospectively determine frequency of thrombosis at 54 venous insertion sites (47 in common femoral veins, seven in right internal jugular veins) after percutaneous placement of Greenfield filters for interruption of the inferior vena cava. Fifty-one filters were successfully placed in 51 patients with a dilator set or a balloon angioplasty catheter. Nine focal thrombi were detected in the common femoral vein (19%) and one in the right internal jugular vein (14%). Use of dilators induced eight thrombi (24%), compared with two (10%) from balloon catheters. The left common femoral vein had a high frequency of thrombosis, regardless of dilation technique (five of nine). Of nine patients with acute common femoral vein thrombosis, four became symptomatic within 10 days after the procedure. Patients may remain asymptomatic or have delayed symptoms; thus, US is valuable for determining patients at risk of thrombosis of the common femoral vein. 相似文献
54.
Saad S. Chris Pietrzykowski J. E. Lewis Sheila S. Stepien Arlene M. Latham Virginia Anne Messick Sherry Ensz Shelley L. Wetherell Carol Behrendt Andrew E. 《Sexuality and disability》1999,17(2):103-113
Prior to this study, there has been little published material about sexual response in women with scleroderma and Sjogren's syndrome. We therefore conducted an investigation of sexual problems and sexual knowledge in women with scleroderma. Eighty-three women with scleroderma participated in the study. Over 37% of respondents reported that they had been diagnosed with Sjogren's syndrome, and 56.9% of respondents reported experiencing sexual problems. Despite these experiences, however, the respondents were remarkably poorly informed about the sexual effects of scleroderma and Sjogren's syndrome. Only 4 women realized that Sjogren's syndrome can cause vaginal dryness. This ignorance is especially appalling when one considers the fact that the study participants were recruited through scleroderma organizations: women who seek out scleroderma organizations are likely to be better informed than the average patient. We urge health care providers to begin to view sexuality education as part of their mission. 相似文献
55.
56.
The replication and activation of both vascular smooth muscle cells and macrophages, which have previously entered the arterial wall, are key events in the atherosclerotic process. The importance of macrophage colony-stimulating factor (MCSF) in control of the growth/proliferation of both cell types confers to this compound a central role in the development of vascular lesions. In order to gain insight into the mechanisms of macrophage proliferation, we investigated the effect of MCSF upon the proliferation of DEL cells. DEL cells constitute a monocyte/histiocytic cell line that differentiates along a macrophage lineage following exposure to phorbol ester. DEL cells constitutively express MCSF, and its receptor MCSFR is encoded by c-fms. We examined whether MCSF might play a role in the proliferation of cultured DEL cells. [3H]Thymidine or 5-bromo-2-deoxyuridine (BrdU) incorporation was measured following the addition of recombinant MCSF or L929 cell supernatant (as a source of MCSF) to quiescent DEL cells. In DEL cells, serum-free L929 cell supernatant induced DNA synthesis in a dose-dependent manner, and such an effect could be blunted by pretreatment of L929 cell supernatant with anti-mouse MCSF antibody. In these cells, DNA synthesis could also be triggered in a dose-dependent manner by the addition of recombinant human MCSF (rh MCSF) or thrombin. These findings clearly show that MCSF influences DEL cell proliferation and suggest an autocrine loop activation. They indicate that MCSF plays an important role in the development of vascular lesions, which occur during atherosclerotic progression. 相似文献
57.
Maggie KM Ma Helen KW Law Kin Sun Tse Kwok Wah Chan Gary CW Chan Desmond YH Yap Maggie MY Mok Lorraine PY Kwan Sydney CW Tang Bo Ying Choy Tak Mao Chan 《International journal of urology》2018,25(5):450-455
Objectives
To evaluate the use of shear wave elastography in assessment of kidney allograft tubulointerstitial fibrosis.Methods
Shear wave elastography assessment was carried out by two independent operators in kidney transplant recipients who underwent allograft biopsy for clinical indications (i.e. rising creatinine >15% or proteinuria >1 g/day). Allograft biopsies were interpreted by the same pathologist according to the 2013 Banff Classification.Results
A total of 40 elastography scans were carried out (median creatinine 172.5 μmol/L [interquartile range 133.8–281.8 μmol/L]). Median tissue stiffness at the cortex (22.6 kPa [interquartile range 18.8–25.7 kPa] vs 22.3 kPa [interquartile range 19.0–26.5 kPa], P = 0.70) and medulla (15.0 kPa [interquartile range 13.7–18.0 kPa] vs 15.6 kPa [interquartile range 14.4–18.2 kPa]) showed no significant differences between the two observers. Interobserver agreement was satisfactory (intraclass correlation coefficient of the cortex 0.84, 95% CI 0.70–0.92 and intraclass correlation coefficient of the medulla 0.88, 95% CI 0.78–0.94). The areas under the receiver operating characteristic curves for detection of tubulointerstitial fibrosis were estimated to be 0.75 (95% CI 0.61–0.89), 0.85 (95% CI 0.75–0.95) and 0.65 (95% CI 0.53–0.78) for cortical, medullary tissue stiffness and serum creatinine, respectively.Conclusions
Shear wave elastography can be used as a non‐invasive tool to evaluate kidney allograft fibrosis with reasonable interobserver agreement and superior test performance to serum creatinine in detecting early tubulointerstitial fibrosis. 相似文献58.
Siejka A Lawnicka H Melen-Mucha G Motylewska E Komorowski J Stepien H 《Recent patents on anti-cancer drug discovery》2012,7(1):56-63
Some of the antagonists of growth hormone-releasing hormone (GHRH) are able to inhibit the growth of various experimental human cancers. The antitumor effects of first antagonists seemed to be dependent mainly on the disruption of pituitary secretion of growth hormone (GH), followed by the reduction in the levels of circulating insulin-like growth factor (IGF)-1, an important growth factor for cancer cells. It seems obvious, that growth hormone deficiency (GHD) induced by GHRH antagonists with all its complications, could limit the beneficial effects of GHRH antagonists therapy, and decrease patients' quality of life. The discovery of local autocrine/paracrine production of GHRH and other related growth factors in many tumoral tissues, in combination with the wide expression of GHRH receptors on cancer cells, directed the research to the synthesis of more potent GHRH antagonists. These compounds exert strong inhibitory effects directly on tumor growth, with scarce endocrine action. The receptor-mediated mechanisms comprise complex and still not completely understood effects on intracellular signaling pathways that are strictly related to human tumorigenesis. This review summarizes recent patents and latest observations on the antineoplastic role of GHRH antagonists in human tumors with emphasis on potential therapeutic applications in clinical oncology. 相似文献
59.
60.