全文获取类型
收费全文 | 345篇 |
免费 | 91篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 3篇 |
妇产科学 | 12篇 |
基础医学 | 121篇 |
口腔科学 | 6篇 |
临床医学 | 31篇 |
内科学 | 80篇 |
皮肤病学 | 7篇 |
神经病学 | 3篇 |
特种医学 | 22篇 |
外科学 | 54篇 |
综合类 | 16篇 |
预防医学 | 18篇 |
眼科学 | 31篇 |
药学 | 13篇 |
肿瘤学 | 15篇 |
出版年
2022年 | 3篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 2篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 9篇 |
2012年 | 3篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 13篇 |
2008年 | 14篇 |
2007年 | 11篇 |
2006年 | 16篇 |
2005年 | 18篇 |
2004年 | 21篇 |
2003年 | 8篇 |
2002年 | 16篇 |
2001年 | 20篇 |
2000年 | 17篇 |
1999年 | 15篇 |
1998年 | 9篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 20篇 |
1991年 | 23篇 |
1990年 | 14篇 |
1989年 | 17篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 5篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 2篇 |
1975年 | 6篇 |
1968年 | 2篇 |
1947年 | 1篇 |
1946年 | 1篇 |
1944年 | 1篇 |
排序方式: 共有436条查询结果,搜索用时 0 毫秒
71.
The assay of secretin in the rat 总被引:2,自引:0,他引:2
N G Heatley 《The Journal of endocrinology》1968,42(4):535-547
72.
73.
Correlation between the measurement of posterior capsule opacification severity and visual function testing 总被引:2,自引:0,他引:2
PURPOSE: To develop software to measure the severity of posterior capsule opacification (PCO) using analysis of retroillumination images and to correlate the results with clinical evaluation of PCO severity and visual function. SETTING: Department of Physics, King's College, and Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom. METHODS: A technique for calculating PCO severity was developed based on calculating the variance of intensity by transforming retroillumination images to a similar mean intensity. The computer-derived severity was compared to grading of clinical severity by 3 independent observers using a library of 100 retroillumination images ranging from clear posterior capsules to very severe PCO. The computer results were also compared with the following other current methods of measuring PCO: Evaluation of Posterior Capsule Opacification (EPCO), POCOman, and Automated Quantification of After-Cataract. A further 35 images were used to compare the results of computer-derived severity with the results of visual function analysis (high-contrast acuity, 100%; low-contrast acuity, 9%) using the Early Treatment Diabetic Retinopathy Study chart, contrast sensitivity testing using the Pelli-Robson chart, and glare assessment using the van den Berg straylight meter. RESULTS: The severity scores showed a good correlation with clinical severity scores for the library of images (r=0.86) and with severity scores using POCOman and EPCO (r=0.85 and r=0.81, respectively). The correlations with visual function tests were also good, with low-contrast visual acuity (9%) showing the best correlation (r=0.87). CONCLUSION: Variance in intensity of PCO was successfully used to calculate the severity of PCO. 相似文献
74.
75.
AIMS: To establish the value of vimentin expression in predicting survival in patients with breast cancer. METHODS: Five-year follow-up data were obtained for 68 patients with ductal carcinoma (NOS) of the breast in whom vimentin expression had been studied in fresh frozen and formalin-fixed, paraffin-embedded tissue. The predictive value on survival of tumour size, growth fraction (as assessed using the Ki67 monoclonal antibody), oestrogen receptor status and Bloom and Richardson grade of the primary tumour, and the presence or absence of lymph node metastases in axillary samples, were also studied. RESULTS: Twenty-two patients died of their disease within 5 years of diagnosis. Vimentin expression either on frozen or paraffin sections did not provide a statistically significant prediction of survival. On univariate analysis tumour grade, size and the presence of lymph node metastases provided prognostic information. Only lymph node status was of independent prognostic importance on multivariate analysis. CONCLUSIONS: Whilst these results confirm the value of established prognostic factors, they do not support the use of vimentin expression in either fresh or fixed tissue for the prediction of survival in ductal carcinoma (NOS) of the breast. 相似文献
76.
Heatley MK 《Histopathology》2008,52(3):267-276
Aims: To compare the relative risk of antigen expression being detected immunohistochemically in ovarian and gastric carcinoma aggregated from studies performed for diagnostic purposes, with the relative risks of their expression in all patients in the English literature.
Methods and results: Both types of series indicated that cytokeratin (CK) 7 expression was greater and that of CK20 and carcinoembryonic antigen less in ovarian than in gastric carcinoma ( P < 0.05). Synthesis of all data available for MUC-2 suggested it was more commonly expressed in ovarian carcinoma, whereas the relative risk in papers that directly compared its expression suggested that it was more common in the gastric carcinoma ( P = 0.2, NS). Aggregating all possible data suggested villin was more likely to be expressed in ovarian cancers, whereas studies in which its expression was compared directly in both tumours suggested the opposite. Although statistically significant, patient numbers were small.
Conclusion: Provided sufficient numbers of cases are studied, analysis of studies comparing antigen expression for diagnostic purposes in tumours from two body sites is likely to be supported in the wider literature. The design of such comparative studies is informed by aggregating data from single tumour studies. 相似文献
Methods and results: Both types of series indicated that cytokeratin (CK) 7 expression was greater and that of CK20 and carcinoembryonic antigen less in ovarian than in gastric carcinoma ( P < 0.05). Synthesis of all data available for MUC-2 suggested it was more commonly expressed in ovarian carcinoma, whereas the relative risk in papers that directly compared its expression suggested that it was more common in the gastric carcinoma ( P = 0.2, NS). Aggregating all possible data suggested villin was more likely to be expressed in ovarian cancers, whereas studies in which its expression was compared directly in both tumours suggested the opposite. Although statistically significant, patient numbers were small.
Conclusion: Provided sufficient numbers of cases are studied, analysis of studies comparing antigen expression for diagnostic purposes in tumours from two body sites is likely to be supported in the wider literature. The design of such comparative studies is informed by aggregating data from single tumour studies. 相似文献
77.
78.
Silvano Bosari Arthur K. C. Lee Giuseppe Viale Gerald J. Heatley Guido Coggi 《Virchows Archiv : an international journal of pathology》1992,421(4):291-295
Summary The expression of thep53 gene product was investigated immunocytochemically in a retrospective series of 164 formalin-fixed paraffin-embedded invasive breast carcinomas with pathologically proven negative lymph nodes. Overall, 78 tumors (48%) showed a variable degree ofp53 immunoreactivity. Among these, 38 cases were low expressors (1–10%p53 immunoreactive tumor cells), 21 moderate expressors (10–50% immunoreactive cells) and 19 high expressors (> 50% immunoreactive cells). Abnormalp53 expression correlated significantly with tumor size, histological and nuclear grade, DNA ploidy, mitotic rate and proliferation index, and with the lack of estrogen receptors. Disease-free and adjusted survival analysis of the 124 node-negative patients with long term (more than 10 years) follow-up, however, did not reveal an independent prognostic role for p53 expression. These data suggest that the evaluation ofp53 immunoreactivity may only play a role in a multiparametric prognostic assessment of node-negative breast carcinoma. 相似文献
79.
A study to compare the immuno-histochemical profile of the human rete ovarii, and epoophoron, with the Fallopian tube and ovarian surface epithelium was performed with 31 antibodies and antisera. A reaction was present in the epithelial cytoplasm of the rete ovarii and epoophoron of mesonephric origin, for vimentin, GFAP, cytokeratin markers, (AE1/AE3, MNF116; Cam 5.2, 34 beta E12 and for the monospecific antibodies to cytokeratins 7 and 19), heat shock protein 27, in the cell membrane for HBME-1, EMA and in the subepithelial collagen for collagen IV. Reactions were present only in the epithelium in the rete ovarii for EGFR (one case) and CA-125 (four cases). A reaction was present in the epithelium of the epoophoron only for Ber-EP-4 and S100. There was no reaction with antibodies for desmin, neurofilament protein, cytokeratins 20 or 14, actin, calretinin, E-cadherin, C-erb-B2, or CEA (monoclonal and polyclonal reagents). The immuno-histochemical profile of the Fallopian tube was consistent with its para-mesonephric origin and that in the ovarian surface epithelium was consistent with a proposed modified mesothelial origin. This study provides an immunohistochemical profile of these structures with a large panel of commonly available antibodies and antisera, confirming and extending the findings described in previous studies. 相似文献
80.
BACKGROUND: We wanted to assess the diagnostic value of pre-endoscopy screening by Helicobacter pylori serology, serum recognition of the CagA and VacA proteins, and serum pepsinogen I levels (sPGI) in patients up to 55 years of age with uncomplicated simple dyspepsia. METHODS: Consecutive dyspeptic patients referred for open-access endoscopy, excluding patients with alarm symptoms, recent intake of acid suppressants, or ingestion of non-steroidal anti-inflammatory drugs. H. pylori status was determined by histology and urease testing. H. pylori serologic status was determined with the enzyme-linked immunosorbent assay (ELISA) and Western blotting, serum recognition of CagA and VacA with Western blot, and sPGI levels by radioimmunoassay. RESULTS: One hundred and fifteen patients were studied (mean age, 40 years: range, 20-55 years), of whom 58 were H. pylori-positive in biopsy-based tests. Twenty-one patients (18%) had significant gastroduodenal lesions (erosions, ulcers, or cancer). The sensitivity (specificity) of the ELISA (optimized) and Western blot in determining H. pylori status was 94.8% (89.5%) and 100% (96.4%), respectively. Screening strategies based on the ELISA or Western blot for determining H. pylori serologic status would have detected 95% or 100% of significant lesions, respectively, and each 'saved' 47% of endoscopies for simple dyspepsia. Serum recognition of the CagA protein would have detected 95% of significant lesions and 'saved' 55% of endoscopies, whereas recognition of the VacA protein would have detected only 81% of the lesions. Screening by H. pylori serology plus a 'low' (<55 ng/ml) or 'high' sPGI (>125 ng/ml) would detect only 57% of significant lesions, although the only case of cancer was included in the hypopepsinogenaemic subgroup of just 11 patients. CONCLUSIONS: In patients with uncomplicated, simple dyspepsia up to 55 years of age, screening by H. pylori serology identified 95%-100% of patients with significant gastroduodenal lesions while potentially saving 46.9% of endoscopies. Serum recognition of the CagA protein identified 95% of lesions and would have saved an additional number of endoscopies (7.9%) compared with basic serology. Measurement of sPGI was of limited diagnostic value. 相似文献