全文获取类型
收费全文 | 621篇 |
免费 | 31篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 49篇 |
妇产科学 | 8篇 |
基础医学 | 69篇 |
口腔科学 | 16篇 |
临床医学 | 83篇 |
内科学 | 129篇 |
皮肤病学 | 32篇 |
神经病学 | 20篇 |
特种医学 | 134篇 |
外科学 | 22篇 |
综合类 | 22篇 |
预防医学 | 23篇 |
眼科学 | 6篇 |
药学 | 14篇 |
1篇 | |
肿瘤学 | 26篇 |
出版年
2022年 | 3篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 8篇 |
2015年 | 10篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 5篇 |
2011年 | 17篇 |
2010年 | 27篇 |
2009年 | 29篇 |
2008年 | 18篇 |
2007年 | 25篇 |
2006年 | 20篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 7篇 |
1998年 | 37篇 |
1997年 | 45篇 |
1996年 | 39篇 |
1995年 | 20篇 |
1994年 | 31篇 |
1993年 | 22篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 24篇 |
1988年 | 20篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 16篇 |
1983年 | 15篇 |
1982年 | 12篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1969年 | 1篇 |
排序方式: 共有657条查询结果,搜索用时 15 毫秒
21.
Busch MP; Laycock M; Kleinman SH; Wages JW Jr; Calabro M; Kaplan JE; Khabbaz RF; Hollingsworth CG 《Blood》1994,83(4):1143-1148
Blood donations in the United States have been screened for antibody to human T-lymphotropic virus type I (HTLV-I) by HTLV-I enzyme immunoassay (EIA) since November 1988. Specimens repeatedly found to be reactive by EIA undergo confirmation by supplementary serologic tests. We assessed the accuracy of blood center testing of 994 HTLV-I EIA repeat-reactive specimens in five US blood centers between November 1988 and December 1991. Of 410 confirmed HTLV-I/II donations, 407 (99.3%) were infected with HTLV-I/II, as determined by polymerase chain reaction (PCR) (403 cases) and by repeat serologic testing (4 cases). The three false- positive results occurred in the first year of testing. Of 425 HTLV- indeterminate specimens, 6 (1.4%) were found to be infected by PCR (5 with HTLV-II and 1 with HTLV-I). None of 159 confirmatory test-negative donations was PCR positive. Of HTLV-I/II-seropositive specimens, 80.2% to 95.4% could be typed as HTLV-I or HTLV-II by type-specific serologic assays. These results support recommendations that HTLV-I/II- seropositive donors should be advised that they are infected with HTLV- I, HTLV-II, or HTLV-I/II (depending on results of type-specific assays). HTLV-indeterminate donors should be advised that their results only rarely indicate HTLV infection. HTLV confirmatory test-negative donors should be reassured that they are not infected with HTLV-I or HTLV-II. 相似文献
22.
作为标准化的非手术治疗,诱导化疗(ICT)在治疗局部晚期头颈鳞癌已有几十年的历史,但是关于其作用尚存争议。同期放化疗(CRT)是目前标准化的非手术治疗,然而由于ICT能够使肿瘤体积缩小,提高放疗的可行性,改善患者对放疗的耐受力,增加放疗后器官功能保留的可能性及降低远处转移率。所以,对ICT的研究从未停止。该文对近期随机试验进行回顾分析,与手术或单独CRT比较,评估ICT中紫杉醇的价值。Meta分析比较ICT中紫杉醇和顺铂及5氟尿嘧啶的作用。之前的随机试验中,并没有ICT提高生存率的报道。但 相似文献
23.
Jared MP Bullard Arshad N Ahsanuddin Anamarija M Perry L Robbin Lindsay Mahmood Iranpour Antonia Dibernardo Paul G Van Caeseele 《The Canadian Journal of Infectious Diseases & Medical Microbiology》2014,25(6):e87-e89
A child with a complicated medical history that included asplenia acquired an infection with Babesia microti in the summer of 2013 and had not travelled outside of Manitoba. Although the clinical findings were subtle, astute laboratory work helped to reach a preliminary identification of Babesia species, while reference laboratory testing confirmed the diagnosis. Blacklegged ticks (Ixodes scapularis) are known to transmit Borrelia burgdorferi and Anaplasma phagocytophilum in the province; however, the present case represents the first known instance of tick-borne B microti, both in Manitoba and in Canada. The expanding territory of the blacklegged tick increases the relevance of this emerging infection. Clinicians, laboratory medical practitioners and public health officials should be aware of B microti as a potential locally acquired infection in Canada. 相似文献
24.
Modern population based oral health management requires a complete understanding of the impact of disease in order to provide efficient and effective oral health care and guidance. Periodontitis is an important cause of tooth loss and has been shown to be associated with a number of systemic conditions. The impact of oral conditions and disorders on quality of life has been extensively studied. However, the impact of periodontitis on quality of life has received less attention. This review summarizes the literature on the impact of periodontitis on oral health‐related quality of life (OHRQoL). Relevant publications were identified after searching the MEDLINE and EMBASE electronic databases. Screening of titles and abstracts and data extraction was conducted. Only observational studies were included in this review. Most of the reviewed studies reported a negative impact of periodontitis on OHRQoL. However, the reporting standards varied across studies. Moreover, most of the studies were conducted in developed countries. 相似文献
25.
Regulation of interleukin-12 expression in human monocytes: selective priming by interferon-gamma of lipopolysaccharide-inducible p35 and p40 genes 总被引:24,自引:4,他引:24
Interleukin-12 (IL-12) is a monocyte/macrophage-derived cytokine that is critical for T lymphocyte and natural killer cell activities and functions. In this study, we examined the regulation of IL-12 expression by human monocytes in response to bacterial lipopolysaccharide (LPS). Several novel aspects of IL-12 induction from monocytes were shown. Optimal expression of IL-12 mRNA and bioactivity required specific priming of monocytes by interferon-gamma (IFN-gamma) before LPS stimulation. Granulocyte-macrophage colony-stimulating factor (GM-CSF) provided an equivalent priming stimulus for LPS-induced tumor necrosis factor (TNF) and IL-12 p40 mRNA, but primed poorly for LPS-inducible p35 message and secreted IL-12 activity. Macrophage colony-stimulating factor (M-CSF), although a potent survival factor for monocytes, showed no priming activity for IL-12 production. Time course experiments demonstrated independent regulation of p40 and p35 by IFN-gamma and LPS. LPS inducibility of p40 expression required only a brief exposure to IFN-gamma (2 hours), while prolonged exposure (+/- 24 hours) to IFN-gamma resulted in diminishing levels of p40 mRNA. p35 inducibility (by LPS) required a longer exposure to IFN-gamma (8 to 16 hours), and continued to be inducible up to 40 hours following IFN- gamma priming. Both mRNAs were rapidly induced (1 to 2 hours) in IFN- gamma-primed monocytes; p35 message reached a plateau by 2 hours, while p40 continued to accumulate. Finally, both p40 and p35 were directly induced by LPS in the presence of cycloheximide. These results indicated that both p40 and p35 are LPS-inducible in monocytes following IFN-gamma pretreatment, and that the regulated expression of p35 controls the level of active IL-12 protein in purified human monocytes. The selectivity of priming by IFN-gamma is in accord with a putative role for IL-12 in the initiation and amplification of TH1-type responses. 相似文献
26.
27.
28.
Novero V; Camus M; Tournaye H; Smitz J; Verheyen G; Joris H; Derde MP; Van Steirteghem AC; Devroey P 《Human reproduction (Oxford, England)》1997,12(1):59-63
Serum follicle stimulating hormone (FSH) is routinely measured when
evaluating the infertile male for intracytoplasmic sperm injection (ICSI).
However, among the sperm parameters, only its relationship with sperm
concentration is well documented. Few investigations concern the
relationship between FSH and sperm motility and morphology, and the results
of ICSI. A retrospective study of 316 couples who underwent ICSI was
carried out to determine the relationships between serum FSH concentrations
in the male and (i) standard sperm parameters_(concentration, motility and
morphology) and (ii) fertilization, cleavage, pregnancy and implantation
rates after ICSI. There was an inverse correlation with sperm concentration
and total motility but no relationship was found with progressive motility
and sperm morphology. Neither was any relationship found between serum FSH
and fertilization, cleavage, pregnancy and implantation rates, and the
results of ICSI. These findings suggest the need to review the routine
measurement of serum FSH in the infertile male when ICSI is the planned
treatment procedure.
相似文献
29.
30.