全文获取类型
收费全文 | 4586篇 |
免费 | 293篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 137篇 |
妇产科学 | 202篇 |
基础医学 | 690篇 |
口腔科学 | 77篇 |
临床医学 | 430篇 |
内科学 | 969篇 |
皮肤病学 | 129篇 |
神经病学 | 406篇 |
特种医学 | 315篇 |
外科学 | 569篇 |
综合类 | 36篇 |
预防医学 | 196篇 |
眼科学 | 87篇 |
药学 | 346篇 |
肿瘤学 | 268篇 |
出版年
2022年 | 27篇 |
2021年 | 45篇 |
2020年 | 36篇 |
2019年 | 52篇 |
2018年 | 59篇 |
2017年 | 58篇 |
2016年 | 68篇 |
2015年 | 71篇 |
2014年 | 98篇 |
2013年 | 111篇 |
2012年 | 149篇 |
2011年 | 181篇 |
2010年 | 138篇 |
2009年 | 146篇 |
2008年 | 180篇 |
2007年 | 220篇 |
2006年 | 198篇 |
2005年 | 167篇 |
2004年 | 177篇 |
2003年 | 148篇 |
2002年 | 158篇 |
2001年 | 148篇 |
2000年 | 185篇 |
1999年 | 138篇 |
1998年 | 96篇 |
1997年 | 102篇 |
1996年 | 85篇 |
1995年 | 71篇 |
1994年 | 48篇 |
1993年 | 70篇 |
1992年 | 110篇 |
1991年 | 106篇 |
1990年 | 94篇 |
1989年 | 102篇 |
1988年 | 77篇 |
1987年 | 69篇 |
1986年 | 63篇 |
1985年 | 81篇 |
1984年 | 52篇 |
1983年 | 72篇 |
1982年 | 36篇 |
1981年 | 46篇 |
1980年 | 41篇 |
1979年 | 44篇 |
1978年 | 36篇 |
1977年 | 34篇 |
1976年 | 28篇 |
1975年 | 27篇 |
1973年 | 31篇 |
1972年 | 30篇 |
排序方式: 共有4923条查询结果,搜索用时 0 毫秒
1.
2.
3.
J M Esteban J A Kuhn B Felder J Y Wong H Battifora J D Beatty P M Wanek J E Shively 《Cancer research》1991,51(14):3802-3806
We have previously shown that the colon carcinoma (LS174T) xenografts that emerged shortly after radioimmunotherapy with 90Y-labeled anti-CEA monoclonal antibody (MAb) ZCE025 lacked significant expression of CEA in comparison with the untreated tumors. The present study was designed to establish if the immunophenotype of the treated tumors was the result of CEA specific therapy and if the effect was permanent. Athymic mice bearing LS174T tumors were treated either with 120 mu Ci of 90Y-ZCE025, an equal dose of 90Y-96.5 (nonspecific MAb), or received no treatment. When the treated tumors grew to approximately 1.5 cm in diameter (6 weeks after therapy), they were resected and aliquoted to be transplanted to other mice, plated in tissue culture, fixed in formalin, and homogenized for CEA quantitation. The procedure was repeated 3 times (a total of 4 months after treatment). The CEA content was evaluated 2 and 6 weeks after therapy and when the tumors were transplanted. We confirmed a 4-fold decrease of CEA in the resurgent tumors 6 weeks after specific 90Y-ZCE025 therapy, which was twice the decrease experienced by the tumors treated with nonspecific 90Y-96.5, indicating substantial and specific killing of CEA-expressing cells. The CEA content slowly but progressively increased with each new pass of the tumor in the mice, reaching approximately one-half the value of the controls at the end of the study. The resurgent tumors were also studied by immunohistochemistry with MAbs detecting different epitopes of CEA, keratin, TAG-72, and epithelial membrane antigen to evaluate possible additional immunophenotypic changes induced by radioimmunotherapy. Only the expression of TAG-72 (recognized by MAb B72.3) increased immediately after therapy, but it returned to the original levels by the end of the study. These results suggest that: (a) specific radioimmunotherapy with 90Y-ZCE025 selectively kills cells that express higher levels of CEA; (b) the immunophenotype of the surviving fraction of the tumor appears to slowly revert to its original form; and (c) other tumor markers unrelated to CEA can also be affected. These observations have important implications for the design of radioimmunotherapy trials. 相似文献
4.
5.
D S Rao R Antonelli K R Kane J E Kuhn C Hetnal 《Henry Ford Hospital medical journal》1991,39(1):41-44
Coexistent primary hyperparathyroidism and monoclonal gammopathy, although rare, has been reported previously by a number of investigators. We report four patients with such an occurrence who were seen between 1976 and 1988. Another patient with primary hyperparathyroidism also had multiple myeloma and was in remission for 12 years. These patients represent approximately 1% of the 386 patients with primary hyperparathyroidism seen during the same 12-year period. Although several mechanisms have been proposed to explain this concurrence, we believe it is the result of a chance occurrence. A review of the literature, an estimate of the chance occurrence of coincidental monoclonal gammopathy, benign or malignant, in patients with primary hyperparathyroidism, and some practical implications of this interesting coexistence are presented. 相似文献
6.
Dr. med. H. Kuhn Dr. med. R. Gerdes-Kuhn Prof. Dr. med. H.-H. Küster 《Fu? & Sprunggelenk》2007,5(1):26-31
The Cinderella shoe syndrome specifies a commonly observed, not yet labeled disproportion of footwear and the morphologic conditions of the wearer. Disproportioned shoes and socks are worn–frequently unconsciously–due to personal reasons, fashion trends, misinformation and wrong advice; they can induce severe foot disorders. The Cinderella shoe syndrome has an important significance within the development, the treatment and the recurrence-prophylaxis of foot disorders, as well as in the assessment of possible reasons for recurrence after foot surgery. To recognize it, to treat individual psychologic reasons, to give support in the choice of footwear, to inform about and to change social reasons are all challenges of the foot surgeon. 相似文献
7.
8.
Holger F. Boehm Felix Eckstein Caecilia Wunderer Volker Kuhn Eva-Maria Lochmueller Karin Schreiber Dirk Mueller Ernst J. Rummeny Thomas M. Link 《Journal of clinical densitometry》2005,8(4):488-494
We tested the hypothesis that bone mineral density (BMD) and bone mineral content (BMC) in proximal human femur specimens in the upper neck region of interest (ROI) and femoral neck axis length (FNAL) provide a significantly better prediction of femoral bone strength than standard ROIs in vitro. BMD and BMC were measured in 110 proximal femur specimens using a standard dual-energy X-ray absorptiometry (DXA) scanner. The analysis included a new ROI in the upper neck as well as the standard ROIs. FNAL was obtained from the scan images. The specimens' failure-load was measured in a mechanical loading device, simulating a fall on the greater trochanter. For the standard ROIs, correlations between failure-load and BMD ranged from R2 = 0.64 (shaft ROI) to R2 = 0.70, p < 0.001 (femoral neck). Prediction of strength by BMD did not significantly differ from those of BMC (R2 ranging from 0.65 to 0.75, p < 0.001). In the upper neck ROI, for both BMD and BMC correlations with failure-load were higher (R2 = 0.76 and 0.81, respectively; p < 0.001). A lower, yet still significant, correlation was found between FNAL and bone strength (R2 = 0.23, p < 0.001). Normalization of failure-load with respect to FNAL did not significantly increase the correlations with densitometric measures. This study provides in vitro evidence indicating that among the ROIs of the proximal femur the newly defined upper neck ROI provides the best prediction of bone strength. Only a weak association was observed between failure load and FNAL. 相似文献
9.
Felix Eckstein Maiko Matsuura Volker Kuhn Mathias Priemel Ralph Müller Thomas M Link Eva-Maria Lochmüller 《Journal of bone and mineral research》2007,22(6):817-824
In this study, we characterize bone microstructure, specifically sex differences, at multiple skeletal sites in 165 subjects >52 yr of age, using microCT technology in vitro. Significant sex differences are observed at the distal radius, femoral neck, and femoral trochanter, but not at the iliac crest, calcaneus, and lumbar vertebral body. Correlations in BV/TV between sites ranged from r = 0.13 to 0.56. INTRODUCTION: The goals of this study were (1) to assess potential sex differences of bone microstructure and their difference between skeletal sites and (2) to explore the relationship of trabecular microstructural properties between relevant skeletal sites. MATERIALS AND METHODS: Trabecular bone microstructural properties were measured in vitro in 165 subjects 52-99 yr of age using microCT. Defined volumes of interest (cylinders with 6 mm diameter and 6 mm length) were scanned at a resolution of 26 microm (isotropic) in six different anatomical sites: distal radius, femoral neck and trochanter, iliac crest, calcaneus, and second lumbar vertebral body. RESULTS: At the radius and femoral neck, trabecular bone displayed a more plate-like structure, thicker trabeculae, smaller separation/higher trabecular number, higher connectivity, and a higher degree of anisotropy in men than in women (p < 0.05). At the trochanter, men displayed more plate-like structure and thicker trabeculae (p < 0.05), but no differences in trabecular separation or other parameters compared with the women. At the calcaneus, iliac crest, and second lumbar vertebra none of the bone parameters displayed significant differences between sexes. The BV/TV at one site explained a range of only 2-32% of the variability at other sites. CONCLUSIONS: These results suggest that trabecular bone microstructural properties are remarkably heterogeneous throughout the skeleton. Significant differences between men and women are observed at some, but not at all, sites. The magnitude of sex differences in trabecular microstructure coincides with that of fracture incidence observed for some of the sites in epidemiological studies. 相似文献
10.
The patterns of cell death and of macrophages were investigated in the forebrain and eyes of the tree shrew Tupaia belangeri during five phases of optic cup formation. Seventeen embryos were studied. Three- dimensional reconstructions were made from one embryo of each phase. In phase 1 (V-shaped optic evagination) a midline band of cell death passes through the closing anterior neuroporus. From phases 2 (optic vesicle) to 5 (far-advanced invagination) the midline band of cell death extends in the dorsal wall of the forebrain to its rostral pole and, further, into its ventral wall. At the approximate future position of the optic chiasm this ventral pycnotic area, predicted but so far unidentified by others, is connected to a previously described second band of cell death passing through the optic anlagen. Recently, evidence has been presented that chicken embryos develop holoprosencephaly and cyclopia when ventral forebrain structures are lost secondary to experimentally induced apoptosis. Our findings in Tupaia suggest that, in cases of spontaneous malformations of this kind, such an atypical pycnotic area in the ventral telencephalon might result from the defective regulation of cell death processes during optic cup formation. In the forebrain and eyes of Tupaia, the occurrence of bands of cell death precedes the appearance of the earliest intraepithelial macrophages. From phase 3 (onset of invagination) onwards almost all of them are concentrated along the band of cell death. 相似文献