全文获取类型
收费全文 | 2542篇 |
免费 | 305篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 12篇 |
儿科学 | 68篇 |
妇产科学 | 31篇 |
基础医学 | 189篇 |
口腔科学 | 81篇 |
临床医学 | 411篇 |
内科学 | 661篇 |
皮肤病学 | 39篇 |
神经病学 | 142篇 |
特种医学 | 317篇 |
外科学 | 196篇 |
综合类 | 22篇 |
预防医学 | 321篇 |
眼科学 | 15篇 |
药学 | 142篇 |
肿瘤学 | 221篇 |
出版年
2023年 | 51篇 |
2022年 | 17篇 |
2021年 | 25篇 |
2020年 | 48篇 |
2019年 | 29篇 |
2018年 | 67篇 |
2017年 | 48篇 |
2016年 | 63篇 |
2015年 | 74篇 |
2014年 | 116篇 |
2013年 | 141篇 |
2012年 | 68篇 |
2011年 | 93篇 |
2010年 | 83篇 |
2009年 | 103篇 |
2008年 | 82篇 |
2007年 | 105篇 |
2006年 | 83篇 |
2005年 | 67篇 |
2004年 | 72篇 |
2003年 | 40篇 |
2002年 | 44篇 |
2001年 | 47篇 |
2000年 | 49篇 |
1999年 | 50篇 |
1998年 | 79篇 |
1997年 | 98篇 |
1996年 | 91篇 |
1995年 | 67篇 |
1994年 | 73篇 |
1993年 | 61篇 |
1992年 | 44篇 |
1991年 | 41篇 |
1990年 | 49篇 |
1989年 | 71篇 |
1988年 | 54篇 |
1987年 | 61篇 |
1986年 | 61篇 |
1985年 | 52篇 |
1984年 | 33篇 |
1983年 | 30篇 |
1982年 | 38篇 |
1981年 | 40篇 |
1980年 | 19篇 |
1979年 | 21篇 |
1978年 | 16篇 |
1977年 | 20篇 |
1976年 | 22篇 |
1975年 | 17篇 |
1974年 | 18篇 |
排序方式: 共有2868条查询结果,搜索用时 15 毫秒
991.
Fefer A; Cheever MA; Thomas ED; Appelbaum FR; Buckner CD; Clift RA; Glucksberg H; Greenberg PD; Johnson FL; Kaplan HG; Sanders JE; Storb R; Weiden PL 《Blood》1981,57(3):421-430
Thirty-four patients aged 4-67 yr (median 17) with acute lymphocytic leukemia (ALL) (18 patients) or acute nonlymphocytic leukemia (ANL) (16 patients) who failed to enter complete remission (CR) or relapsed on conventional chemotherapy were treated with cyclophosphamide (CY), 60 mg/kg/day for 2 days, 1000 rad total body irradiation, and a marrow transplant from a genotypically identical normal twin. Sixteen of the patients received additional chemotherapy within the week before CY. After the transplant, 23 patients received immunotherapy consisting of killed autologous leukemic cells and/or normal twin peripheral blood lymphocytes, 16 as part of a prospectively randomized study. One moribund patient died before engraftment. Nine patients (6 ALL, 3 ANL) continued to have detectable leukemic cells. Twenty-four patients (70%) achieved CR. One of them died of viral hepatitis at 1 mo and another of viral interstitial pneumonitis at 4 mo in CR. Fourteen patients (7 ALL, 7 ANL) relapsed 2-16 mo (median 4) after transplantation. However, 8 patients (24%) (3 ALL, 5 ANL) remain in CR without any maintenance chemotherapy at 29-103 mo (median 80) after the transplant. The end results were not signficantly influenced by the type of leukemia, the immediated pre-CY chemotherapy, or the immunotherapy. The results show that this approach, even when applied to endstage patients with acute leukemia in relapse, causes tolerable morbidity, rare nonleukemic deaths, and frequent remissions, some of which represent cures. 相似文献
992.
993.
994.
F B Petersen R A Bowden M Thornquist J D Meyers C D Buckner G W Counts N Nelson B A Newton K M Sullivan J McIver 《Bone marrow transplantation》1987,2(2):141-147
Ninety-seven patients randomized to receive (45 patients) or not to receive (52 patients) intravenous cytomegalovirus immune globulin before and after allogeneic marrow transplantation were evaluated retrospectively for the occurrence of bacterial and fungal septicemia in the first 100 days post-transplant. In a proportional hazards regression test, infection prevention regimens, immunoglobulin administration, age and occurrence of acute graft-versus-host disease were tested simultaneously for the occurrence of septicemia in the pre- and post-engraftment period. Of these factors, only patients receiving immunoglobulin had significantly fewer episodes of septicemia following engraftment with 11 (26%) patients in the globulin group having 14 episodes compared to 22 (42%) patients in the control group having 27 episodes (p = 0.039). None of the patients experienced complications with the immunoglobulin infusions. These results suggest that the administration of intravenous immunoglobulin may be a practical and effective method to decrease the incidence of septicemia following marrow transplantation. 相似文献
995.
996.
Poldrack RA; Desmond JE; Glover GH; Gabrieli JD 《Cerebral cortex (New York, N.Y. : 1991)》1998,8(1):1-10
The learning of perceptual skills is thought to rely upon multiple regions
in the cerebral cortex, but imaging studies have not yet provided evidence
about the changes in neural activity that accompany visual skill learning.
Functional magnetic resonance imaging (fMRI) was used to examine changes in
activation of posterior brain regions associated with the acquisition of
mirror-reading skill for novel and practiced stimuli. Multiple regions in
the occipital lobe, inferior temporal cortex, superior parietal cortex and
cerebellum were involved in the reading of mirror-reversed compared to
normally oriented text. For novel stimuli, skilled mirror-reading was
associated with decreased activation in the right superior parietal cortex
and posterior occipital regions and increased activation in the left
inferior temporal lobe. These results suggest that learning to read mirror-
reversed text involves a progression from visuospatial transformation to
direct recognition of transformed letters. Reading practiced, relative to
unpracticed, stimuli was associated with decreased activation in occipital
visual cortices, inferior temporal cortex and superior parietal cortex and
increased activation in occipito-parietal and lateral temporal regions. By
examining skill learning and item- specific repetition priming in the same
task, this study demonstrates that both of these forms of learning exhibit
shifts in the set of neural structures that contribute to performance.
相似文献
997.
Fernando López MD PhD FEBORL‐HNS Kenneth O. Devaney MD JD FCAP Ehab Y. Hanna MD 《Head & neck》2016,38(12):1847-1854
The sinonasal cavities are rare locations for metastases. Metastases to these locations are usually solitary and produce similar symptoms to those of a primary sinonasal tumor. Nasal obstruction and epistaxis are the most frequent symptoms. The maxillary sinus is most frequently involved. The most common primary tumor sites to spread to this region originate in the kidney, breast, thyroid, and prostate, although any malignancy could potentially lead to a metastasis to the paranasal sinuses. The patient's prognosis is usually poor because of the fact that the sinonasal metastasis is usually associated with widespread disseminated disease. In the majority of patients, palliative therapy is the only possible treatment option. Nevertheless, whenever possible, surgical excision either alone or combined with radiotherapy may be useful for palliation of symptoms and, rarely, to achieve prolonged survival. This review considers the most interesting cases reported in the literature that presents metastases to the sinonasal cavities. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1847–1854, 2016 相似文献
998.
999.
1000.
A review of the literature on bacteriologic and nonbacteriologic criteria for identifying individuals at high risk to dental caries is presented. The studies have been evaluated on the basis of 1) their ability to predict future caries activity of individuals and 2) their practical use. Single measurements of past caries experience in the primary and permanent dentitions, filled tooth surfaces, and S. mutans in dental plaque and saliva were found to have limited value in identifying individuals that later would develop carious lesions, as judged from the low values of sensitivity and specificity. Lactobacilli counts in saliva indicated some evidence of high reliability as a basis for selecting patients susceptible to dental decay. The results of these studies, however, were not comparable because of variations in methods, critical value of the screening criteria, and age and size of the samples. A combination of two or more predictors showed promising results, as the predictive value was increased. More research is needed on appropriate screening methods to provide higher reliability and validity of the predictors. 相似文献