全文获取类型
收费全文 | 3358篇 |
免费 | 204篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 70篇 |
妇产科学 | 64篇 |
基础医学 | 559篇 |
口腔科学 | 142篇 |
临床医学 | 245篇 |
内科学 | 671篇 |
皮肤病学 | 80篇 |
神经病学 | 265篇 |
特种医学 | 279篇 |
外科学 | 362篇 |
综合类 | 20篇 |
预防医学 | 158篇 |
眼科学 | 20篇 |
药学 | 228篇 |
中国医学 | 2篇 |
肿瘤学 | 411篇 |
出版年
2023年 | 17篇 |
2022年 | 30篇 |
2021年 | 57篇 |
2020年 | 50篇 |
2019年 | 72篇 |
2018年 | 106篇 |
2017年 | 63篇 |
2016年 | 73篇 |
2015年 | 68篇 |
2014年 | 130篇 |
2013年 | 175篇 |
2012年 | 275篇 |
2011年 | 232篇 |
2010年 | 132篇 |
2009年 | 136篇 |
2008年 | 213篇 |
2007年 | 198篇 |
2006年 | 188篇 |
2005年 | 199篇 |
2004年 | 201篇 |
2003年 | 157篇 |
2002年 | 135篇 |
2001年 | 34篇 |
2000年 | 23篇 |
1999年 | 27篇 |
1998年 | 61篇 |
1997年 | 51篇 |
1996年 | 27篇 |
1995年 | 42篇 |
1994年 | 30篇 |
1993年 | 37篇 |
1992年 | 25篇 |
1991年 | 18篇 |
1990年 | 26篇 |
1989年 | 37篇 |
1988年 | 23篇 |
1987年 | 32篇 |
1986年 | 25篇 |
1985年 | 24篇 |
1984年 | 18篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 19篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 10篇 |
1972年 | 5篇 |
排序方式: 共有3589条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Perfluorochemicals as US contrast agents for tumor imaging and hepatosplenography: preliminary clinical results 总被引:3,自引:0,他引:3
Mattrey RF; Strich G; Shelton RE; Gosink BB; Leopold GR; Lee T; Forsythe J 《Radiology》1987,163(2):339-343
In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients. 相似文献
6.
P Wattiau B Bernier P Deslée T Michiels G R Cornelis 《Proceedings of the National Academy of Sciences of the United States of America》1994,91(22):10493-10497
Pathogenic yersiniae secrete anti-host proteins called Yops, by a recently discovered Sec-independent pathway. The Yops do not have a classical signal peptide at their N terminus and they are not processed during membrane translocation. The secretion domain is nevertheless contained in their N-terminal part but these domains do not resemble each other in the different Yops. We have previously shown that YopE secretion requires SycE, a 15-kDa acidic protein acting as a specific cytosolic chaperone. Here we show that the gene downstream from yopH encodes a 16-kDa acidic protein that binds to hybrid proteins made of the N-terminal part of YopH and either the bacterial alkaline phosphatase or the cholera toxin B subunit. Loss of this protein by mutagenesis led to accumulation of YopH in the cytoplasm and to a severe and selective reduction of YopH secretion. This protein thus behaves like the counterpart of SycE and we called it SycH. We also engineered a mutation in lcrH, the gene upstream from yopB and yopD, known to encode a 19-kDa acidic protein. Although this mutation was nonpolar, the mutant no longer secreted YopB and YopD. The product of lcrH could be immunoprecipitated together with cytoplasmic YopD. lcrH therefore seems to encode a YopD-specific chaperone, which we called SycD. Determination of the dependence of YopB on SycD requires further investigation. SycE, SycH, and SycD appear to be members of a new family of cytosolic chaperones required for Yop secretion. 相似文献
7.
Walking exercise in patients with intermittent claudication. Experience in routine clinical practice.
下载免费PDF全文
![点击此处可从《The British journal of general practice》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Marie-Louise Bartelink Henri E J H Stoffers Cornelis J Biesheuvel Arno W Hoes 《The British journal of general practice》2004,54(500):196-200
BACKGROUND: In patients with intermittent claudication, exercise in the form of walking is effective in reducing pain and maximising achievable walking distance. However, data are lacking on the implementation of walking exercise in these patients. AIMS: To explore the current behaviour and views of patients with intermittent claudication towards taking walking exercise. DESIGN OF STUDY: Postal questionnaire and focus group meetings. SETTING: Two academic general practice networks (Utrecht and Maastricht Universities) in The Netherlands. METHOD: Three hundred and seventy-five patients with intermittent claudication, selected from the files of general practitioners participating in two academic general practice networks, were sent a postal questionnaire; 216 (58%) were returned. Nine of these responders also attended a focus group meeting. RESULTS: Seventy per cent (151/216) of the patients reported having received advice about walking exercise. If specified, the advice given most often recommended walking in the local neighbourhood (56%, 84/151). Fifty-two per cent (113/216) of all patients actually performed walking exercise and only 32%of them received any kind of supervision. Among the barriers for taking walking exercise, 'comorbidity', 'lack of (specific) advice' and 'lack of supervision' were often mentioned. Among the stimuli to start and continue walking, 'following the doctor's advice', 'relief of complaints' and 'a better general condition' were often mentioned by patients. CONCLUSIONS: Walking exercise was not carried out by almost half of patients with intermittent claudication in this study. Lack of specific advice and supervision were found to be important barriers to taking walking exercise. 相似文献
8.
Daniel N. Streblow Craig N. Kreklywich Patricia Smith Jordana L. Soule Christine Meyer Michael Yin Patrick Beisser Cornelis Vink Jay A. Nelson Susan L. Orloff 《American journal of transplantation》2005,5(3):436-442
Cytomegalovirus (CMV) infection accelerates transplant vascular sclerosis (TVS) and chronic rejection (CR) in both human and animal solid organ transplantation models. The host/viral mechanisms involved in this process are unclear. We examine the role of the rat CMV (RCMV)-encoded chemokine-receptor R33 in the development of TVS using a rat heart transplantation/CR model. F344 heart grafts were transplanted heterotopically into Lewis recipients. The ability of RCMV lacking the R33 gene (RCMV-Deltar33) to accelerate CR/TVS (neointimal index, NI) was compared to wild-type (WT) RCMV. Allograft recipients were infected with 1 x 10(5) pfu RCMV or RCMV-Deltar33 on postoperative day (POD) 1. Grafts from RCMV-Deltar33-infected recipients demonstrated an accelerated time to allograft CR compared to grafts from uninfected recipients (POD = 56 vs. 90), this was slower than that seen in grafts from WT-RCMV-infected recipients (POD = 45). Similarly, the degree of graft TVS formation at terminal rejection in RMCV-Deltar33 infected recipients was more severe than uninfected recipients (NI = 63 vs. 45), yet not as severe as in WT-RCMV infected recipients (NI = 83). In parallel, RCMV-Deltar33 failed to induce vascular smooth muscle cell (SMC) migration in vitro, whereas WT-RCMV induced substantial migration. The RCMV-encoded chemokine-receptor r33 is critical for RCMV-accelerated TVS/CR and vascular SMC migration. 相似文献
9.
10.
W A Cornelis 《American journal of hospital pharmacy》1986,43(7):1685-1686