全文获取类型
收费全文 | 959篇 |
免费 | 38篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 73篇 |
妇产科学 | 21篇 |
基础医学 | 81篇 |
口腔科学 | 46篇 |
临床医学 | 81篇 |
内科学 | 266篇 |
皮肤病学 | 26篇 |
神经病学 | 49篇 |
特种医学 | 160篇 |
外科学 | 67篇 |
综合类 | 18篇 |
预防医学 | 46篇 |
眼科学 | 7篇 |
药学 | 31篇 |
中国医学 | 1篇 |
肿瘤学 | 23篇 |
出版年
2021年 | 12篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 8篇 |
2014年 | 26篇 |
2013年 | 28篇 |
2012年 | 17篇 |
2011年 | 30篇 |
2010年 | 37篇 |
2009年 | 36篇 |
2008年 | 31篇 |
2007年 | 25篇 |
2006年 | 23篇 |
2005年 | 28篇 |
2004年 | 32篇 |
2003年 | 25篇 |
2002年 | 21篇 |
2001年 | 19篇 |
2000年 | 30篇 |
1999年 | 31篇 |
1998年 | 30篇 |
1997年 | 41篇 |
1996年 | 49篇 |
1995年 | 30篇 |
1994年 | 29篇 |
1993年 | 36篇 |
1992年 | 10篇 |
1991年 | 14篇 |
1990年 | 18篇 |
1989年 | 25篇 |
1988年 | 19篇 |
1987年 | 27篇 |
1986年 | 32篇 |
1985年 | 15篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 21篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1978年 | 4篇 |
1977年 | 13篇 |
1976年 | 9篇 |
1975年 | 8篇 |
1974年 | 5篇 |
1973年 | 7篇 |
1972年 | 7篇 |
1971年 | 5篇 |
排序方式: 共有1003条查询结果,搜索用时 46 毫秒
1.
D Gröne† R Treudler† EM de Villiers‡ R Husak† CE Orfanos† ChC Zouboulis†§ 《Journal of the European Academy of Dermatology and Venereology》2006,20(2):202-205
Cidofovir is an acyclic nucleoside phosphonate with broad-spectrum activity against DNA viruses, including human papilloma virus (HPV). However, data on the efficacy of cidofovir in an immunosuppressive setting remain contradictory. We report for the first time on the promotion of the healing of recalcitrant warts in a patient with myelodysplastic syndrome with intravenous cidofovir treatment. 相似文献
2.
Assault-injured Adolescents Presenting to the Emergency Department: Causes and Circumstances 总被引:1,自引:0,他引:1
3.
4.
K E Steidley S H Thompson M J McQuade S L Strong M J Scheidt T E Van Dyke 《Journal of periodontology》1992,63(9):753-756
Previous reports describe a characteristic, rapidly progressive, periodontitis that is unique to patients who are seropositive for HIV antibody (Western blot +). The purpose of this study was to compare the T4 and T8 lymphocyte subpopulations in the peripheral blood and periodontal lesions of these HIV patients with those of healthy controls. T-cell subsets in peripheral blood were quantified by flow cytometry. The values from this analysis were used to calculate the peripheral T4:T8 lymphocyte ratio for each patient. Gingival tissue (papilla) was obtained from 8 HIV+ patients and from 6 healthy HIV- control patients during routine gingival surgery. The T-cell subpopulations in the gingival tissue were determined using serial cryostat sections that were labeled with monoclonal antibodies for T4 and T8 cells and developed using an avidin-biotin-peroxidase system. Six sections were taken from each of the 14 tissue specimens (one per patient). The sections were examined at 450 x and the mean number of T4 and T8 cells calculated for each section. These mean values were then used to determine the T4:T8 lymphocyte ratio for each tissue specimen. The peripheral blood analysis revealed a mean serum T4:T8 ratio of (2.07 +/- 0.455) for the controls and (0.58 +/- 0.26) for the HIV patients. The significantly lower T4:T8 ratio in HIV patients is consistent with their diagnosis. Although the results indicated that the mean T4:T8 lymphocyte ratio in the gingiva of controls was highly variable (2.70 +/- 1.344), the gingiva of HIV patients consistently exhibited a complete absence of T-cells.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
5.
6.
Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance 总被引:3,自引:0,他引:3
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy. 相似文献
7.
8.
Steenbergen EJ; Verhagen OJ; van Leeuwen EF; van den Berg H; von dem Borne AE; van der Schoot CE 《Blood》1995,86(2):692-702
Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL. 相似文献
9.
Picotamide inhibition of excess in vitro thromboxane B2 release by colorectal mucosa in inflammatory bowel disease. 总被引:1,自引:0,他引:1
Collins CE Benson MJ Burnham WR Rampton DS 《Alimentary pharmacology & therapeutics》1996,10(3):315-320
BACKGROUND: Inflammatory bowel disease is associated with increased mucosal release of eicosanoids. Among these, thromboxane A2 has been proposed as a possible inflammatory mediator; its suppression may be a useful therapeutic option. METHODS: Using a tissue incubation technique, we compared release of immunoreactive thromboxane B2 by colonic biopsies from patients with ulcerative colitis, Crohn's disease and controls, and assessed the inhibitory effect of picotamide, a thromboxane synthesis inhibitor-receptor antagonist, which has been widely used in Italy for management of ischaemic heart and cerebrovascular disease. RESULTS: Increased amounts of thromboxane B2 were released from biopsies from patients with active ulcerative colitis (median 238 pg/20 min/mg wet weight (interquartile range 147- 325), n = 12) and active Crohn's disease (252 (174-450), 6) compared with those from patients with quiescent ulcerative colitis (95 (61- 140), 12) or Crohn's disease (105 (57-201), 13), or controls (136 (64- 206), 8). Incubation with picotamide at concentrations between 100 microM and 1 mM reduced thromboxane B2 release (IC50 890 microM). CONCLUSION: Since increased thromboxane A2 production may have pathogenetic importance, thromboxane synthesis inhibitor-receptor antagonists such as picotamide merit therapeutic trial in the management of inflammatory bowel disease. 相似文献
10.