全文获取类型
收费全文 | 2999794篇 |
免费 | 232757篇 |
国内免费 | 5178篇 |
专业分类
耳鼻咽喉 | 43513篇 |
儿科学 | 89189篇 |
妇产科学 | 78670篇 |
基础医学 | 422907篇 |
口腔科学 | 88164篇 |
临床医学 | 270746篇 |
内科学 | 584785篇 |
皮肤病学 | 61423篇 |
神经病学 | 247381篇 |
特种医学 | 119207篇 |
外国民族医学 | 941篇 |
外科学 | 461819篇 |
综合类 | 68317篇 |
现状与发展 | 2篇 |
一般理论 | 1156篇 |
预防医学 | 232863篇 |
眼科学 | 70708篇 |
药学 | 227673篇 |
7篇 | |
中国医学 | 5884篇 |
肿瘤学 | 162374篇 |
出版年
2018年 | 29832篇 |
2016年 | 25547篇 |
2015年 | 28946篇 |
2014年 | 41254篇 |
2013年 | 62401篇 |
2012年 | 84348篇 |
2011年 | 88937篇 |
2010年 | 52454篇 |
2009年 | 50225篇 |
2008年 | 85089篇 |
2007年 | 90171篇 |
2006年 | 91529篇 |
2005年 | 89092篇 |
2004年 | 85870篇 |
2003年 | 82776篇 |
2002年 | 81681篇 |
2001年 | 145862篇 |
2000年 | 151109篇 |
1999年 | 127588篇 |
1998年 | 34967篇 |
1997年 | 31559篇 |
1996年 | 31381篇 |
1995年 | 30184篇 |
1994年 | 28337篇 |
1993年 | 26317篇 |
1992年 | 101956篇 |
1991年 | 98371篇 |
1990年 | 95019篇 |
1989年 | 91960篇 |
1988年 | 85006篇 |
1987年 | 83393篇 |
1986年 | 78833篇 |
1985年 | 75383篇 |
1984年 | 56247篇 |
1983年 | 47970篇 |
1982年 | 28009篇 |
1981年 | 24834篇 |
1980年 | 23208篇 |
1979年 | 52158篇 |
1978年 | 36259篇 |
1977年 | 30771篇 |
1976年 | 28318篇 |
1975年 | 30249篇 |
1974年 | 37211篇 |
1973年 | 35293篇 |
1972年 | 33190篇 |
1971年 | 30874篇 |
1970年 | 29087篇 |
1969年 | 27224篇 |
1968年 | 24713篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
Ohne Zusammenfassung 相似文献
142.
BCR-ABL activity and its response to drugs can be determined in CD34+ CML stem cells by CrkL phosphorylation status using flow cytometry. 总被引:2,自引:0,他引:2
A Hamilton L Elrick S Myssina M Copland H J?rgensen J V Melo T Holyoake 《Leukemia》2006,20(6):1035-1039
In chronic myeloid leukaemia, CD34(+) stem/progenitor cells appear resistant to imatinib mesylate (IM) in vitro and in vivo. To investigate the underlying mechanism(s) of IM resistance, it is essential to quantify Bcr-Abl kinase status at the stem cell level. We developed a flow cytometry method to measure CrkL phosphorylation (P-CrkL) in samples with <10(4) cells. The method was first validated in wild-type (K562) and mutant (BAF3) BCR-ABL(+) as well as BCR-ABL(-) (HL60) cell lines. In response to increasing IM concentration, there was a linear reduction in P-CrkL, which was Bcr-Abl specific and correlated with known resistance. The results were comparable to those from Western blotting. The method also proved to be reproducible with small samples of normal and Ph(+) CD34(+) cells and was able to discriminate between Ph(-), sensitive and resistant Ph(+) cells. This assay should now enable investigators to unravel the mechanism(s) of IM resistance in stem cells. 相似文献
143.
144.
We evaluated the acquisition and performance of a high-precision locomotor task in patients with Parkinson's disease (PD) and healthy subjects. All subjects walked on a treadmill and had to step repetitively as low as possible over an obstacle without touching it. During blocks 1 and 2, the subjects had full vision and received additional acoustic warning and feedback signals. During block 3, vision became restricted. Changes in foot clearance and the number of obstacle hits were evaluated. Initially, PD patients performed poorer and improved foot clearance slower. After task repetition, the groups performed similarly. Restricting vision deteriorated performance in both groups. The similar performance of PD patients after task repetition might indicate that adequate training could improve adaptive locomotor behavior in PD patients. 相似文献
145.
F Pitta T Troosters V S Probst M A Spruit M Decramer R Gosselink 《The European respiratory journal》2006,27(5):1040-1055
Accurate assessment of the amount and intensity of physical activity in daily life is considered very important due to the close relationship between physical activity level, health, disability and mortality. For this reason, assessment of physical activity in daily life has gained interest in recent years, especially in sedentary populations, such as patients with chronic obstructive pulmonary disease (COPD). The present article aims to compare and discuss the two kinds of instruments more commonly used to quantify the amount of physical activity performed by COPD patients in daily life: subjective methods (questionnaires, diaries) and motion sensors (electronic or mechanical methods). Their characteristics are summarised and evidence of their validity, reliability and sensitivity is discussed, when available. Subjective methods have practical value mainly in providing the patients' view on their performance in activities of daily living and functional status. However, care must be taken when using subjective methods to accurately quantify the amount of daily physical activity performed. More accurate information is likely to be available with motion sensors rather than questionnaires. The selection of which motion sensor to use for quantification of physical activity in daily life should depend mainly on the purpose of its use. 相似文献
146.
J Müller-Quernheim K I Gaede E Fireman G Zissel 《The European respiratory journal》2006,27(6):1190-1195
An increase in chronic beryllium disease (CBD) has been suggested due to higher industrial use of beryllium alloys. Since occupational CBD is a perfect phenocopy of sarcoidosis, it might be misdiagnosed as sarcoidosis. In the current it was hypothesised that CBD exists in cohorts of sarcoidosis patients. In a prospective case study, sarcoidosis patients were evaluated for potential beryllium exposure. In those patients in whom beryllium exposure was confirmed and beryllium hypersensitivity demonstrated, the diagnosis of sarcoidosis was rejected and corrected to CBD. In 84 patients seen for re-evaluation or making a diagnosis of sarcoidosis, beryllium exposure was recognised and a diagnosis of CBD was made in 34 out of 84 patients. The time lag between clinical diagnosis of sarcoidosis and the final diagnosis of CBD ranged 0-18 yrs (median 3 yrs) and the mean (range) age at time of diagnosis of CBD was 43.9(25-80) yrs. Beryllium-contaminated workplaces causing disease encompassed a wide spectrum of industries and technical trades in which beryllium-exposure is generally not perceived as a health hazard. In conclusion, chronic beryllium disease still belongs to the spectrum of differential diagnoses of granulomatous disorders. 相似文献
147.
C T Gan G P McCann J T Marcus S A van Wolferen J W Twisk A Boonstra P E Postmus A Vonk-Noordegraaf 《The European respiratory journal》2006,28(6):1190-1194
The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function. 相似文献
148.
149.
C. Ballet G. Roussey-Kesler J.-T. Aubin S. Brouard M. Giral P. Miqueu S. Louis S. van der Werf J.-P. Soulillou 《American journal of transplantation》2006,6(11):2796-2801
Rare kidney allograft recipients enjoy unaltered graft function years after interruption of their immunosuppressive treatment. To assess the extent to which this state of 'operational tolerance' (TOL) is specific to the graft and not the result of a global immunodeficiency, we analyzed the response of such patients following influenza vaccination. Hemagglutination inhibition titers and frequency of IFNgamma-secreting T cells were measured before 1 and 3 months after vaccination. The proportion of healthy volunteers (HV) responding to vaccine was significantly higher than that of immunosuppressed (IS) patients. Three 'TOL' patients presented a humoral response similar to that of HV, whereas the two others had a poor response, like the IS recipients. Although the small number of patients does not allow for definitive conclusions to be made, these data suggest that the status of tolerance may be heterogeneous, with some patients with a global immunodeficiency and others with an adapted response to vaccination. 相似文献
150.
M. J. Englesbe S. J. Pelletier S. Kheterpal M. O'Reilly D. A. Campbell Jr. 《American journal of transplantation》2006,6(4):666-670
The severity of illness in transplant patients and the complexity of transplant operations results in significant postoperative morbidity and mortality. Remarkable efforts have been made by transplant physicians to study and improve organ allocation, graft and patient survival, immunosuppression and the long-term management of post-transplant complications. Less effort has been spent studying the actual transplant operation and systems of acute transplant care. The National Surgical Quality Improvement Program (NSQIP) has provided a standardized approach to quality improvement and has demonstrated significant potential for a reduction in postoperative morbidity and mortality in other surgical disciplines. Medical centers are under increasing pressure to measure surgical quality and the nexus of transplant surgical quality improvement should not lie in the hands of CMS or JACHO, but rather it should be created and developed within the transplant community. The time has come for a national transplant surgical quality improvement program based on the NSQIP infrastructure. Such a proactive approach toward quality improvement from the transplant community is an excellent investment for patients, providers and health care payers. 相似文献