全文获取类型
收费全文 | 6344篇 |
免费 | 479篇 |
国内免费 | 86篇 |
专业分类
耳鼻咽喉 | 57篇 |
儿科学 | 275篇 |
妇产科学 | 166篇 |
基础医学 | 913篇 |
口腔科学 | 127篇 |
临床医学 | 763篇 |
内科学 | 1301篇 |
皮肤病学 | 133篇 |
神经病学 | 781篇 |
特种医学 | 629篇 |
外国民族医学 | 1篇 |
外科学 | 787篇 |
综合类 | 113篇 |
预防医学 | 323篇 |
眼科学 | 41篇 |
药学 | 238篇 |
中国医学 | 5篇 |
肿瘤学 | 256篇 |
出版年
2021年 | 76篇 |
2019年 | 55篇 |
2018年 | 74篇 |
2017年 | 56篇 |
2016年 | 69篇 |
2015年 | 107篇 |
2014年 | 132篇 |
2013年 | 177篇 |
2012年 | 233篇 |
2011年 | 235篇 |
2010年 | 164篇 |
2009年 | 140篇 |
2008年 | 251篇 |
2007年 | 289篇 |
2006年 | 215篇 |
2005年 | 235篇 |
2004年 | 213篇 |
2003年 | 233篇 |
2002年 | 215篇 |
2001年 | 187篇 |
2000年 | 203篇 |
1999年 | 161篇 |
1998年 | 195篇 |
1997年 | 160篇 |
1996年 | 167篇 |
1995年 | 124篇 |
1994年 | 128篇 |
1993年 | 110篇 |
1992年 | 123篇 |
1991年 | 132篇 |
1990年 | 122篇 |
1989年 | 107篇 |
1988年 | 146篇 |
1987年 | 131篇 |
1986年 | 130篇 |
1985年 | 110篇 |
1984年 | 90篇 |
1983年 | 90篇 |
1982年 | 67篇 |
1981年 | 64篇 |
1980年 | 57篇 |
1979年 | 63篇 |
1978年 | 73篇 |
1977年 | 66篇 |
1976年 | 61篇 |
1975年 | 38篇 |
1974年 | 43篇 |
1973年 | 47篇 |
1972年 | 50篇 |
1969年 | 44篇 |
排序方式: 共有6909条查询结果,搜索用时 250 毫秒
31.
Y Leskinen JP Salenius T Lehtim?ki H Huhtala H Saha 《American journal of kidney diseases》2002,40(3):472-479
BACKGROUND: Knowledge of the prevalence of peripheral arterial disease (PAD) in patients with chronic renal failure (CRF) is limited because of a lack of uniformity in disease definition and recognition. Furthermore, little is known of the prevalence of medial arterial calcification (MAC) in patients with CRF. Our goal is to study the prevalence of PAD and MAC defined by ankle brachial index (ABI) or toe brachial index (TBI) measurements in a Finnish population of patients with CRF consisting of predialysis and dialysis patients, as well as renal transplant recipients. METHODS: We examined 136 patients with CRF and 59 control subjects. Fifty-nine of the patients with CRF had moderate to severe predialysis CRF, 36 patients were on dialysis treatment, and 41 were renal transplant recipients. Mean age of patients was 51.9 +/- 11.5 years, and 39 patients (29%) had diabetes. ABI and TBI were measured by means of photoplethysmography. The definition of PAD required an ABI value of 0.90 or less, a TBI value of 0.60 or less, or a previous positive lower-extremity angiogram result. ABI values of 1.3 or greater or incompressible arteries at ankle level indicated MAC. The presence of claudication was determined by an interview. RESULTS: Prevalences of PAD on this study were 22.0% in patients with predialysis CRF, 30.6% in patients on dialysis treatment, 14.6% in renal transplant recipients, and 1.7% in the control group (P = 0.001). Prevalences of MAC were 23.7%, 41.7%, 23.1%, and 3.4% (P < 0.001), respectively. Only 9 patients had claudication, and 6 of those patients had PAD. CONCLUSION: Both asymptomatic PAD and MAC are common in patients with CRF. Therefore, we recommend the use of both ABI and TBI measurements in the evaluation of PAD in patients with CRF. 相似文献
32.
We used arthrotomography to study the glenoid labrum in 114 patients. Sixty-nine of the patients had anatomic instability of the shoulder (including recurrent dislocation and subluxation of the shoulder), and 45 patients had functional instability of the shoulder (denoted by chronic pain, clicking of the joint, and the sensation that an unstable condition exists without the objective signs of it). Labral tears were revealed arthrotomographically in 86% of the patients with anatomic instability, while only 40% of the patients with functional instability had labral abnormalities, and these were primarily of minor severity. Fifty-six patients (44 of whom had anatomic instability; 12, functional instability) required surgery. The surgical findings were correlated with the arthrotomographic findings, and no false-positive results were revealed. However, arthrotomography demonstrated only part of the pathologic condition of two patients. These results confirm that there is a strong correlation between labral pathologic conditions and anatomic instability of the shoulder. Arthrotomographic studies have a great impact on the selection of therapy in cases of both anatomic and functional instability of the shoulder. 相似文献
33.
34.
35.
M. Müller R. Heicappell F. Habermann M. Kaufmann U. Steiner K. Miller 《Urological research》1997,25(3):187-192
CD44 is the principal cell surface receptor for hyaluronate. Variant forms of the receptor, produced by alternative splicing, have been found to be associated with tumor progression in a variety of cancers. Based on investigations at the RNA level, it has recently been proposed that expression of CD44 variant V2 was present in urothelial cancer but not in normal urothelium. Since a distinctive marker for urothelial cancer would be extremely useful, frozen sections of normal urothelium and urothelial cancer were examined for expression of standard CD44 and CD44V2. Frozen sections of specimens of 35 patients with transitional cell carcinoma of the bladder, 16 specimens of normal bladder and 5 ureters were examined. Immunohistochemical staining was performed using a polyclonal antibody to CD44V2 (PAB CD44V2), a monoclonal antibody to CD44V2 (MAB CD44V2) and a monoclonal antibody to CD44S (MAB CD44S). CD44V2 and CD44S were also measured in lysates of urine sediments from 21 patients by enzyme-linked immunoabsorbent assay (ELISA). All investigated transitional cell carcinomas expressed CD44V2. There was no differentiation between invasive and noninvasive carcinoma. CD44V2 was also expressed in normal urothelium. Standard CD44 was expressed by the transitional cell carcinoma, normal urothelium, musculature and interstitial tissue. The amount of CD44V2 and CD44S in lysates of urine sediments is not correlated to diagnosis. In contrast to investigations at the RNA level, CD44V2 on the protein level seems not to be a distinctive marker for urothelial cancer. Therefore, CD44V2 will not be a useful diagnostic marker for detection of transitional cell carcinoma. 相似文献
36.
T. J. Vogl S. Steiner B. Schnell A. Gerbes C. McMahon C. Wilimzig J. Lissner 《European radiology》1992,2(4):310-316
Twenty-nine patients with diffuse liver disease were examined by ultrasound, CT and MRI. MRI was performed using T1- and T2-weighted spin-echo sequences as well as fast gradient-echo-sequences. The paramagnetic contrast agent Gd-DTPA was applied intravenously (0.1 mmol/kg). in patients with hepatitis, MRI could be used in guiding liver biopsies as inflammatory changes were clearly delineated. CT and ultrasound were superior to MRI in the detection of focal or diffuse fatty degeneration. On the other hand MRI was more helpful in differentiating fatty changes and neoplasm. In liver cirrhosis, fibrotic changes were most clearly demonstrated by MRI. In patients suffering from hemochromatosis MRI offers advantages over CT and ultrasound in the diagnosis and follow up due to the paramagnetic properties of iron, resulting in a reduction in signal intensity. In patients with Wilson's disease a characteristic pattern of parenchymal changes was seen. Administration of Gd- DTPA contributes additional information about perfusion conditions in the liver parenchyma, however this information was not of diagnostic relevance in the cases we studied.
Correspondence to: T.J. Vogl 相似文献
37.
38.
Pernes JM; Vitoux JF; Brenoit P; Raynaud A; Parola JL; Roth JP; Angel CY; Fiessinger JN; Roncato M; Gaux JC 《Radiology》1986,158(2):481-485
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs. 相似文献
39.
40.