全文获取类型
收费全文 | 1448篇 |
免费 | 100篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 57篇 |
妇产科学 | 35篇 |
基础医学 | 136篇 |
口腔科学 | 12篇 |
临床医学 | 136篇 |
内科学 | 186篇 |
皮肤病学 | 8篇 |
神经病学 | 217篇 |
特种医学 | 42篇 |
外科学 | 130篇 |
综合类 | 54篇 |
预防医学 | 378篇 |
眼科学 | 10篇 |
药学 | 90篇 |
肿瘤学 | 57篇 |
出版年
2023年 | 7篇 |
2022年 | 19篇 |
2021年 | 24篇 |
2020年 | 26篇 |
2019年 | 27篇 |
2018年 | 28篇 |
2017年 | 16篇 |
2016年 | 23篇 |
2015年 | 29篇 |
2014年 | 36篇 |
2013年 | 48篇 |
2012年 | 68篇 |
2011年 | 101篇 |
2010年 | 45篇 |
2009年 | 54篇 |
2008年 | 90篇 |
2007年 | 92篇 |
2006年 | 103篇 |
2005年 | 89篇 |
2004年 | 78篇 |
2003年 | 88篇 |
2002年 | 83篇 |
2001年 | 21篇 |
2000年 | 16篇 |
1999年 | 23篇 |
1998年 | 12篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 8篇 |
1992年 | 7篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 11篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 8篇 |
1978年 | 6篇 |
1976年 | 7篇 |
1974年 | 6篇 |
1973年 | 11篇 |
1971年 | 6篇 |
1970年 | 8篇 |
1959年 | 7篇 |
1958年 | 10篇 |
1957年 | 21篇 |
1956年 | 19篇 |
1955年 | 12篇 |
1954年 | 15篇 |
1949年 | 7篇 |
排序方式: 共有1549条查询结果,搜索用时 15 毫秒
1.
2.
3.
Cardiac output was measured by gated magnetic resonance imaging (MRI) and by thermodilution in four mongrel dogs. The entire heart was examined in contiguous slices at end-diastole and end-systole in a plane parallel to the interventricular septum. Each set of images was analyzed for chamber volume using a custom computer program to evaluate each pixel. No geometric assumptions were made. Cardiac output was calculated for right and left ventricles and compared with the thermodilution data. We found that the cardiac output of the right ventricle compared well with that of the left ventricle and that both fell within the range measured by thermodilution. Cardiac-gated MRI has the potential to assess the cardiac output of both the right and left ventricles. Comparison between right ventricular and left ventricular function will permit quantification of left to right shunting or unilateral ventricular volume overload. 相似文献
4.
5.
6.
Evaluation of a Commercial PCR Kit for Diagnosis of Cytomegalovirus Infection of the Central Nervous System 总被引:3,自引:2,他引:1
下载免费PDF全文
![点击此处可从《Journal of clinical microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Adriana Weinberg Debbie Spiers Guan-Yung Cai Christopher M. Long Rita Sun Vince Tevere 《Journal of clinical microbiology》1998,36(11):3382-3384
We evaluated the AMPLICOR cytomegalovirus (CMV) PCR kit for the diagnosis of neurologic CMV infections on 43 positive and 112 negative archived cerebrospinal fluid specimens originally tested by an in-house PCR method. The AMPLICOR kit showed sensitivity and specificity of 95 and 100%, respectively, versus the home-grown assay, indicating its utility in this clinical setting. 相似文献
7.
Peripancreatic lymphoadenopathy and extrahepatic immunological manifestations in chronic hepatitis C 总被引:1,自引:0,他引:1
S. NERI C. M. BRUNO G. D'ANGELO S. RUSSO 《European journal of clinical investigation》1996,26(8):665-667
Abstract. The aim of the study was to determine the role of peripancreatic lymph node swelling in systemic immunological alterations during chronic hepatitis C (HC). The prospective study was carried out as a clinical study in a university hospital. Clinical, haematochemical and ultrasonographic findings in 182 patients were studied. Ultrasonography was performed by the same operator and the findings were evaluated blind without the operator knowing the clinical and haematochemical parameters. Hepatitis B virus (HBV) markers, anti-HCV antibodies. LKMl, cryoglobulinaemia, rheumatoid factor and anti-tissue antibodies were determined. Liver biopsy was carried out in 43 of the 182 patients. One or two pathological peripancreatic lymph nodes (PLNs) were present in 30 of the 182 patients and, of the 30, 28 were anti-HC positive. Only one patient in the non-PLN group was positive for anti-HCV, there being statistical significance ( P <0.0001) between the PLN and non-PLN groups. In HCV-positive patients, extrahepatic immunological manifestations were observed (cryoglobulinaemia; positivity to anti-smooth muscle, antinuclear and antimitochondrial antibodies; positivity to rheumatoid factor and LKMl). In five patients the presence of focal lymphocytic aggregates was detected by biopsy, whereas one patient presented typical ocular lesion of Mikulicz's syndrome. Our results may confirm the marked lymphotropism shown by the HC virus and indicate more complex immune system involvement, especially in view of the coexisting signs of immune system involvement related to the presence of intrahepatic cellular aggregates detected in our study. We believe that the peripancreatic adenopathy in chronic HCV hepatitis is an important diagnostic sign and may indicate an involvement of the C virus in the still unexplained extrahepatic immunological disorders. 相似文献
8.
Mohamad H Yamani Randall C Starling James B Young Daniel Cook Yang Yu D Geoffrey Vince Patrick McCarthy Norman B Ratliff 《The Journal of heart and lung transplantation》2002,21(9):983-989
BACKGROUND: A cascade of inflammatory reactions characterize acute vascular rejection after heart transplantation. This study was undertaken to test the hypothesis that acute vascular rejection is associated with up-regulation of vitronectin receptor (alphavbeta3), increased expression of tissue factor, and activation of the extracellular matrix metalloproteinase induction system. METHODS: Acute vascular rejection developed in 14 heart transplant recipients within 2 weeks of transplantation, confirmed by immunofluorescence (AVR group). We compared these patients with 10 transplant recipients who had no evidence of acute vascular rejection or peritransplant ischemic injury (control group). We evaluated endomyocardial biopsy specimens for alphavbeta3, tissue factor, and extracellular matrix metalloproteinase inducer (EMMPRIN). RESULTS: Compared with the control group, the AVR group demonstrated evidence of significantly increased expression of alphavbeta3 (1.9-fold, p < 0.001), tissue factor (1.8-fold, p < 0.001), and EMMPRIN (1.5-fold, p < 0.001). All patients in the AVR group received plasmapheresis; 11 of 14 patients had evidence of ischemic necrosis on biopsy specimens, and 3 of 14 patients experienced hemodynamic compromise and graft dysfunction and died within 3 weeks of transplant. Another patient died at 10 months after transplant. CONCLUSIONS: Acute vascular rejection is associated with up-regulation of alphavbeta3, tissue factor, and activation of the matrix metalloproteinase induction system, which may contribute to the lethal morbidity associated with this disease. 相似文献
9.
10.
Endometrial integrin expression in women undergoing IVF and ICSI: a comparison of the two groups and fertile controls 总被引:4,自引:0,他引:4
Thomas K Thomson AJ Wood SJ Kingsland CR Vince G Lewis-Jones DI 《Human reproduction (Oxford, England)》2003,18(2):364-369
BACKGROUND: Integrins are thought to play a vital role in implantation. Three integrins in particular (alpha(4)beta(1), alpha(v)beta(3) and alpha(1)beta(1)) are all present during the implantation window. Defects in their expression have been linked to tubal disease, unexplained infertility and endometriosis. Hence, a reduced endometrial integrin expression would be expected in women attending for IVF due to these causes of infertility when compared with those with male factor infertility attending for ICSI. METHODS: Women attending for IVF (n = 25) and ICSI (n = 25) treatment were recruited, and timed endometrial biopsies were taken during the 'implantation window' (cycle day 20-24). A group of fertile women (n = 15) attending for sterilization was used as controls. RESULTS: There was no significant difference in integrin expression between patients undergoing IVF or ICSI. Neither did these groups differ from the control group. CONCLUSIONS: The endometrium in patients undergoing ICSI treatment is sometimes thought to be more receptive, as the infertility might be due to a male factor. This study shows that there is no significant difference in integrin expression between patients attending for IVF or ICSI and the control group. These data add to the increasing uncertainty about the clinical value of assessing the endometrium with only one marker, in this case integrins. 相似文献