全文获取类型
收费全文 | 1551篇 |
免费 | 125篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 71篇 |
妇产科学 | 19篇 |
基础医学 | 198篇 |
口腔科学 | 34篇 |
临床医学 | 218篇 |
内科学 | 354篇 |
皮肤病学 | 26篇 |
神经病学 | 28篇 |
特种医学 | 342篇 |
外科学 | 196篇 |
综合类 | 24篇 |
预防医学 | 51篇 |
眼科学 | 5篇 |
药学 | 99篇 |
肿瘤学 | 87篇 |
出版年
2021年 | 11篇 |
2019年 | 9篇 |
2018年 | 20篇 |
2017年 | 19篇 |
2016年 | 21篇 |
2015年 | 19篇 |
2014年 | 31篇 |
2013年 | 33篇 |
2012年 | 35篇 |
2011年 | 40篇 |
2010年 | 40篇 |
2009年 | 49篇 |
2008年 | 47篇 |
2007年 | 84篇 |
2006年 | 15篇 |
2005年 | 40篇 |
2004年 | 30篇 |
2003年 | 29篇 |
2002年 | 35篇 |
2001年 | 43篇 |
2000年 | 34篇 |
1999年 | 41篇 |
1998年 | 78篇 |
1997年 | 87篇 |
1996年 | 61篇 |
1995年 | 76篇 |
1994年 | 47篇 |
1993年 | 44篇 |
1992年 | 41篇 |
1991年 | 32篇 |
1990年 | 28篇 |
1989年 | 57篇 |
1988年 | 51篇 |
1987年 | 37篇 |
1986年 | 40篇 |
1985年 | 53篇 |
1984年 | 26篇 |
1983年 | 25篇 |
1982年 | 32篇 |
1981年 | 19篇 |
1980年 | 28篇 |
1979年 | 21篇 |
1978年 | 13篇 |
1977年 | 29篇 |
1976年 | 24篇 |
1975年 | 18篇 |
1974年 | 9篇 |
1972年 | 7篇 |
1971年 | 6篇 |
1970年 | 10篇 |
排序方式: 共有1754条查询结果,搜索用时 0 毫秒
81.
KA Bergman JF Meis AM Horrevorts L Monnens 《Acta paediatrica (Oslo, Norway : 1992)》1992,81(9):709-711
Systemic candidiasis with renal involvement is a rare but well-recognized complication during intensive care treatment in very-low-birth-weight infants. We report a term neonate who developed anuria associated with bilateral bezoar formation in the renal pelvis and candidemia. The treatment consisted of placement of a nephrostomy tube in the left kidney, short-term irrigation with amphotericin B and iv, and later, oral administration of fluconazole. 相似文献
82.
83.
84.
85.
Wang JF; Bashir M; Engelsberg BN; Witmer C; Rozmiarek H; Billings PC 《Carcinogenesis》1997,18(2):371-375
Chromium (Cr) is a human carcinogen and a potent DNA damaging agent.
Incubation of DNA with CrCl3 resulted in dose-dependent binding of Cr to
DNA and, at concentrations >20 microM, altered the electrophoretic
mobility of a 100 bp oligonucleotide. We also demonstrate that high
mobility group (HMG) proteins 1 and 2 bind Cr-damaged DNA (Cr-DNA). Protein
binding was lesion density-dependent, with maximal binding to DNA treated
with 100 microM CrCl3. HMG2 binds to Cr-DNA with a calculated Kd of
approximately 10(-9) M. These proteins also bound DNA obtained from
chromate-treated cells. These results suggest that the covalent attachment
of Cr to DNA induces alterations in DNA structure which are recognized by
HMG1 and HMG2. Therefore, these proteins may function as Cr-damaged DNA
recognition proteins in vivo and as a consequence of binding, may play a
role in directing the cellular response to Cr-DNA adduct formation.
相似文献
86.
P Greally MJ Hussein AJ Cook AP Sampson PJ Piper JF Price 《Archives of disease in childhood》1993,68(3):389-392
It is postulated that a vigorous host inflammatory response in the cystic fibrosis lung contributes to lung injury. Tumour necrosis factor-alpha (TNF-alpha) may play a part in that process and in the generation of leukotrienes. Therefore, the relationships between sputum TNF-alpha, leukotriene concentration, and lung function abnormalities in 16 children with cystic fibrosis were investigated. Each subject provided sputum samples and performed spirometry. TNF-alpha was measured by enzyme linked immunosorbent assay; individual leukotrienes were separated using high performance liquid chromatography and quantified by radioimmunoassay. The geometric mean concentration of TNF-alpha was 129.7 pg/ml and 95% confidence interval 48.2 to 348.3. Mean (SEM) leukotriene B4 (LTB4) was 97.8 (22.9) pmol/g and total cysteinyl leukotrienes were 60.9 (14.8) pmol/g. Mean (SD) forced expiratory volume in one second (FEV1) of the group was 53 (15)% of predicted and forced vital capacity (FVC) was 65 (14)% of predicted. There was a significant positive correlation between TNF-alpha and both LTB4 and the total cysteinyl leukotriene sputum content. An inverse relationship existed between TNF-alpha and FEV1 and FVC. Moreover, a negative correlation was observed between sputum LTB4 and FEV1 and FVC. These results suggest that TNF-alpha and the leukotrienes may participate in the airways inflammation and airflow obstruction observed in cystic fibrosis subjects and support the hypothesis that TNF-alpha upregulates the 5-lipoxygenase pathway in vivo. 相似文献
87.
The cytokines interleukin-1 and interleukin-2 participate in the inflammatory response, and may contribute to hypergammaglobulinaemia G and the development of lung injury in cystic fibrosis. Anti-inflammatory treatment with corticosteroids may attenuate this response. The effect of a 12 week course of oral prednisolone on spirometry and serum concentrations of interleukin-1 alpha (IL-1 alpha), soluble interleukin-2 receptor (sIL-2R), and IgG was investigated in 24 children with cystic fibrosis. Prednisolone was administered, in a double blind and placebo controlled manner, at an initial dose of 2 mg/kg daily for 14 days and tapered to 1 mg/kg on alternate days for 10 weeks. The treated group (n = 12) experienced an increase in forced expiratory volume in one second and forced vital capacity at 14 days, however, these changes were smaller at 12 weeks. In the treated group, change in pulmonary function was associated with decreased serum IgG and cytokine concentrations. Prednisolone suppresses serum concentrations of these cytokines, which may participate in the inflammatory response, the excessive synthesis of IgG, and airflow obstruction observed in cystic fibrosis patients. 相似文献
88.
Human B cell activation. Evidence for diverse signals provided by various monoclonal anti-IgM antibodies 总被引:5,自引:2,他引:3 下载免费PDF全文
Seven murine monoclonal antibodies (mAb) with different binding characteristics for human IgM varied markedly in their ability to induce proliferation of T cell-depleted human splenocytes. Two mAb (HB57 and 5D7) that bound to distinct epitopes on IgM were highly effective initiators of B cell proliferation at very low concentrations, in the presence of a T cell factor source. In the absence of T cell supernatant, both HB57 and 5D7 mAbs produced a markedly reduced degree of stimulation at all concentrations. Two additional anti-IgM mAb (VIIIE11 and Mu53) were distinctive in that, even at high concentrations, only limited proliferation was observed compared with the first group of mAb. This proliferation depended on the presence of T cell supernatant. Competitive-binding studies revealed that the epitope recognized by mAb Mu53 may be identical or very proximate to that recognized by HB57. Three other mAb (1G6, XG9, and P24) induced little or no proliferation. 1G6 bound to a unique epitope on the IgM molecule, whereas XG9 shared a determinant with VIIIE11 mAb. Regulatory influences of Fc receptor binding cannot account for all the diversity in proliferation observed with the individual anti-IgM mAb. Markedly augmented proliferation was obtained when B cells were cultured with certain combinations of anti-IgM mAb in the presence of exogenous T cell supernatant. The proliferation induced in the absence of T cell supernatant by high concentrations of mAb mixtures that included 1G6 approached that observed for the same mixtures in the presence of T cell supernatant. The data suggest that certain signals delivered through membrane IgM can bypass the need for T cell supernatant in the activation of human B lymphocytes. 相似文献
89.
90.