全文获取类型
收费全文 | 351篇 |
免费 | 23篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 27篇 |
妇产科学 | 4篇 |
基础医学 | 26篇 |
口腔科学 | 6篇 |
临床医学 | 49篇 |
内科学 | 93篇 |
皮肤病学 | 11篇 |
神经病学 | 10篇 |
特种医学 | 71篇 |
外科学 | 10篇 |
综合类 | 8篇 |
预防医学 | 12篇 |
眼科学 | 2篇 |
药学 | 39篇 |
肿瘤学 | 16篇 |
出版年
2023年 | 2篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 8篇 |
2012年 | 6篇 |
2011年 | 12篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 9篇 |
2007年 | 26篇 |
2006年 | 6篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 7篇 |
1999年 | 6篇 |
1998年 | 14篇 |
1997年 | 21篇 |
1996年 | 22篇 |
1995年 | 18篇 |
1994年 | 14篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 4篇 |
1990年 | 14篇 |
1989年 | 21篇 |
1988年 | 16篇 |
1987年 | 15篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 6篇 |
1959年 | 1篇 |
排序方式: 共有390条查询结果,搜索用时 31 毫秒
101.
Karen S. Calhoun Paula Matherne 《Journal of behavior therapy and experimental psychiatry》1975,6(2):139-143
Three schedules of time-out were compared for suppressing aggressive behavior in a 7-yr-old retarded girl. The schedules (FR5, FR2, CRF) were time-out after every 5th, 2nd or every aggressive act. The FR5 schedule had no effect on rate of aggressive behavior while the FR2 and CRF schedules both produced significant reductions, the CRF being more effective. This reduction was maintained at follow-up after 5 weeks. It appears that time-out may be effective proportionate to the percentage of target behaviors it follows, and that some success can be achieved with less than continuous application. 相似文献
102.
103.
104.
Rhodococcus equi is an aerobic Gram-positive and acid-fast coccobacillus that may cause cavitary pneumonia in immunocompromised hosts such as HIV-infected patients. Numerous Grocott's methenamine silver (GMS)-positive organisms were initially noted on the direct smear; a minor number of acid-fast organisms were seen in the Thin-Prep slide. Since the abundant mucous material with the attached organisms seen in conventional smears may be lost in liquid-based preparations, more sensitive stains such as Fite, as well as a more diligent search for organisms, is needed. This case illustrates the importance of careful selection and evaluation of special stains in sputum specimens. 相似文献
105.
106.
Hydroxyurea increases hemoglobin F levels and improves the effectiveness of erythropoiesis in beta-thalassemia/hemoglobin E disease 总被引:5,自引:0,他引:5
Fucharoen S; Siritanaratkul N; Winichagoon P; Chowthaworn J; Siriboon W; Muangsup W; Chaicharoen S; Poolsup N; Chindavijak B; Pootrakul P; Piankijagum A; Schechter AN; Rodgers GP 《Blood》1996,87(3):887-892
Hydroxyurea (HU) is one of several agents that have been shown to enhance hemoglobin (Hb) F levels in patients with sickle cell disease and may be useful as a therapy for beta-globinopathies. However, limited information exists on the effects of HU in patients with thalassemia. Accordingly, we examined the hematologic effects of orally administered HU in 13 patients with beta-thalassemia/Hb E, including four patients who had been splenectomized. These patients were treated with escalating doses (final range, 10 to 20 mg/kg/d) for 5 months and were observed in the outpatient hematology clinic every 2 to 4 weeks. Complete blood counts including reticulocyte counts, amounts of Hb E and Hb F, G gamma:A gamma and alpha:non-alpha globin biosynthetic ratios were evaluated before and during treatment. Almost all patients responded with an average increase of 33% in Hb F levels, from a mean (+/- SD) of 42% +/- 11% to 56% +/- 8% (P < .0001), and a reciprocal decline in the percentage of Hb E from 59% +/- 9% to 49% +/- 8% (P < .001). Reticulocytosis was decreased from a mean (+/- SD) of 18.0% +/- 15.6% to 11.7% +/- 9.1% (P < .05); there was also a slight (10%) but statistically significant increase in hemoglobin levels and an improved balance in alpha:non-alpha globin chains ratios. The side effects were minimal in most patients, although these patients tended to tolerate a lower dose of HU before significant myelosuppression than has been our previous experience in sickle cell disease. One splenectomized patient died of sepsis during the trial. We conclude that increased Hb F production in beta-thalassemia/Hb E patients, with an improvement in the alpha:non-alpha globin ratios and, probably, the effectiveness of erythropoiesis, can be achieved using HU. Longer trials of HU in this population, including at other doses and in combination with other agents, appear warranted. 相似文献
107.
Mononuclear leukocytes isloated from the blood of previously treated patients with advanced active Hodgkin disease contained high concentrations of monocytes and showed poor lymphocyte blastogenesis to mitogens. In five of eight patients with disseminated disease, blastogenesis became normal or improved markedly when the leukocyte suspensions were depleted of monocytes before culture. Addition of autologous macrophages to the monocyte-depleted lymphocytes resulted in a reappearance of the inhibition of blastogenesis. Monocyte inhibition was associated with the presence of active disease, lymphocytopenia, and low lymphocyte/monocyte ratios in the peripheral blood. The role of previous treatment is uncertain, since inhibition tended to disappear when the patients were retreated. Inhibitory monocyte-lymphocyte interactions may be one of the causes of impaired cell-mediated immunity in Hodgkin disease. 相似文献
108.
Interactive MR-guided biopsy in an open-configuration MR imaging system 总被引:15,自引:0,他引:15
109.
110.
Magnetic resonance (MR) imaging of the trachea and main bronchi was performed in seven infants (aged 3-15 months) with symptoms of airway obstruction. Diagnoses made clinically, radiologically, and by transnasal flexible fiberoptic endoscopy included vascular ring (one patient), tracheal compression by the innominate artery (five patients), and tracheomalacia (one patient). MR images in sagittal and axial sections clearly demonstrated tracheal compression at the level of the innominate artery in three infants and tracheal narrowing due to a vascular ring in one patient. The other three patients had airway narrowing apparently unrelated to aberrant vascular structures on MR images. The appearance of the airways on MR images corresponded closely to endoscopic observations. It is concluded that MR imaging is capable of demonstrating airway obstruction in infants and delineating any relationship to major mediastinal blood vessels. 相似文献