全文获取类型
收费全文 | 61429篇 |
免费 | 4415篇 |
国内免费 | 1967篇 |
专业分类
耳鼻咽喉 | 472篇 |
儿科学 | 1297篇 |
妇产科学 | 3143篇 |
基础医学 | 7565篇 |
口腔科学 | 1270篇 |
临床医学 | 5006篇 |
内科学 | 6144篇 |
皮肤病学 | 852篇 |
神经病学 | 4188篇 |
特种医学 | 1652篇 |
外国民族医学 | 7篇 |
外科学 | 4782篇 |
综合类 | 9049篇 |
现状与发展 | 3篇 |
一般理论 | 6篇 |
预防医学 | 5385篇 |
眼科学 | 1681篇 |
药学 | 7788篇 |
67篇 | |
中国医学 | 4787篇 |
肿瘤学 | 2667篇 |
出版年
2024年 | 105篇 |
2023年 | 844篇 |
2022年 | 1163篇 |
2021年 | 2169篇 |
2020年 | 1968篇 |
2019年 | 1958篇 |
2018年 | 1905篇 |
2017年 | 1911篇 |
2016年 | 1888篇 |
2015年 | 1805篇 |
2014年 | 3473篇 |
2013年 | 4412篇 |
2012年 | 3447篇 |
2011年 | 3895篇 |
2010年 | 3127篇 |
2009年 | 2815篇 |
2008年 | 2778篇 |
2007年 | 2848篇 |
2006年 | 2514篇 |
2005年 | 2303篇 |
2004年 | 1935篇 |
2003年 | 1928篇 |
2002年 | 1478篇 |
2001年 | 1395篇 |
2000年 | 1123篇 |
1999年 | 1121篇 |
1998年 | 932篇 |
1997年 | 930篇 |
1996年 | 895篇 |
1995年 | 909篇 |
1994年 | 744篇 |
1993年 | 656篇 |
1992年 | 592篇 |
1991年 | 521篇 |
1990年 | 526篇 |
1989年 | 461篇 |
1988年 | 345篇 |
1987年 | 288篇 |
1986年 | 340篇 |
1985年 | 462篇 |
1984年 | 438篇 |
1983年 | 266篇 |
1982年 | 342篇 |
1981年 | 276篇 |
1980年 | 299篇 |
1979年 | 221篇 |
1978年 | 183篇 |
1977年 | 172篇 |
1976年 | 158篇 |
1975年 | 113篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
As a consequence of the time-varying magnetic field induced by eddy currents, frequency drifting occurs when the sampling window of localized spectroscopy continuously shifts. The frequency drifting and the concomitant phase variations can severely affect spectroscopy results when data are acquired with multiple echo times (TEs), such as in the measurement of glutamate (Glu) concentration using the TE-averaged method. Specifically, the averaged spectra are further broadened and distorted in the presence of residual eddy currents, and editing of the coupled spins of Glu C4 protons is affected, resulting in errors in the measured relative intensity ratio. Postacquisition correction using unsuppressed water as reference can effectively minimize this detrimental effect, as manifested by the significantly enhanced signal intensity. Also, it is demonstrated that the methyl signals of creatine (Cr) at 3.0 ppm and choline (Cho) at 3.2 ppm can be used as internal references in finding frequency and phase disparities between different TEs. 相似文献
72.
Laurent Boyer Patrice Francois Elisabeth Doutre Georges Weil Jose Labarere 《International journal for quality in health care》2006,18(5):359-364
OBJECTIVE: . The aim of this study was to assess clinical staff's opinions on the results of in-patient satisfaction surveys and their use within the quality improvement process. SETTING: The institution is a 2200-bed teaching hospital of tertiary health care employing 8000 professionals. Patient satisfaction surveys are carried out each year using a validated questionnaire mailed to a random sample of patients. The specific results of each department are sent to the medical and paramedical managers. METHODS: We conducted a questionnaire survey on 500 care providers randomly selected in every medical and surgical department. RESULTS: A total of 261 questionnaires were returned and analysed. Overall, 94% of responders had a favourable opinion of the patient satisfaction surveys. They considered that the patient was able to judge hospital service quality, especially in its relational, organizational, and environmental dimensions. The specific results for the department were less well known than the overall hospital results (60 versus 76%). These results were formally discussed in the department according to 40% of responders; 40% declared that these data resulted in improvement actions and considered that they led to modifications in their behaviour with patients. CONCLUSIONS: Despite a declared interest in satisfaction surveys, the results remain underused by hospital staff and insufficiently discussed within teams. 相似文献
73.
74.
75.
76.
目的:应用原位PCR技术检测B细胞系恶性淋巴瘤。方法:采用免疫球蛋白重链(IgH)基因第三互补决定区(CDR-Ⅲ)的引物,dig-11-dUTP标记物,应用直接原位PCR技术检测Ⅲ-Ⅳ级恶性淋巴瘤的间期淋巴细胞,结果:在初诊的15例恶性淋巴瘤患中,12例检测到IgH基因重排;4例临床表现呈现淋巴瘤性白血病患,治疗后骨髓完全缓解,2例间期细胞原位PCR仍显示有IgH基因重排,6个月复发,结论:间期细胞原位PCR技术能敏感、准确地检测Ⅲ级以上的恶性淋巴瘤,并帮助预测复发,为一有效的基因诊断方法。 相似文献
77.
Sachiko Goto Akiyoshi Tsuji Teiko Murai Minoru Nishida Hiroko Tsukano Haruo Watanabe 《Journal of infection and chemotherapy》1998,4(1):16-19
Although there are effective antibacterial agents against plague, newer antibacterial agents have been developed which show
more potent activity against other bacterial organisms, but have not been tested againstYersinia pestis. A strain ofYersinia pestis was selected (no. 22; National Institute of Infectious Diseases, Tokyo, Japan) that caused a systemic infection in mice.Y. pestis no. 22 was intraperitoneally inoculated into DDY-strain mice, and 13 oral or 6 injectable antibacterial drugs given to the
infected mice at varying doses 1 and 24 hours after infection. Levofloxacin, sparfloxacin and ofloxacin were the most effective
oral agents against the infection, and prulifloxacin and pazufloxacin were also effective but to a lesser extent. Also, gentamicin
and arbekacin were the most potent injectable antibacterial agents againstY. pestis. These results suggest that there are several new drugs, both oral and injectable, which exert excellent in vivo antibacterial
activity against a mouse infection model and may be useful for the clinical treatment of plague. 相似文献
78.
Basic fibroblast growth factor mRNA, bFGF peptide and FGF receptor in epiretinal membranes of intraocular proliferative disorders (PVR and PDR) 总被引:3,自引:0,他引:3
Arno Hueber Peter Wiedemann Peter Esser Klaus Heimann 《International ophthalmology》1997,20(6):345-350
Basic fibroblast growth factor (bFGF) has been shown to be involved in epiretinal membrane formation in proliferative vitreoretinal disorders. However, up to now, little knowledge exists, as to the actual cellular source of this potent mitogen.We examined 20 epiretinal membranes from patients with proliferative diabetic retinopathy (PDR) (n = 12) and proliferative vitreoretinopathy (PVR) (n = 8) for the presence of bFGF peptide, fibroblast growth factor receptor-1 (FGFR-1) and bFGF messenger ribonucleic acid (mRNA).Using a specific antibody, we detected bFGF peptide in most (8/10) examined PDR membranes and in all (8/8) PVR membranes. Moreover, we found positive staining for the corresponding receptor.Local production of bFGF in epiretinal membranes was confirmed by nonisotopic in situ hybridisation for bFGF mRNA in some (4/7) examined PDR membranes and some (3/4) examined PVR membranes. All membranes which contained bFGF mRNA were also positive for bFGF peptide.In conclusion, bFGF is produced and stored in epiretinal membranes. Together with the corresponding receptor, bFGF may play a role in the auto- and paracrine control of the proliferative processes at the vitroretinal interface.Abbreviations aFGF
acidic fibroblast growth factor
- bFGF
basic fibroblast growth factor
- FGFR-1
fibroblast growth factor receptor-1
- mRNA
messenger ribonucleic acid 相似文献
79.
80.
Tracy Brightman Jiang-Hong Ye Elizabeth Ortiz-Jimenez Edward J. Flynn Wen-Hsien Wu Joseph J. McArdle 《Brain research》1995,678(1-2)
While adult mice receiving picrotoxin (PTX) alone responded with clonic and tonic-clonic seizures, this response was greatly suppressed for mice simultaneously injected with 2,3-butanedione monoxime (BDM). For example, 60% and 10% of the mice convulsed when injected (i.p.) with 3.0 mg/kg PTX alone or PTX plus 205 mg/kg of BDM, respectively. In contrast, a non-oxime analogue of BDM, 2,3-butanedione (BTD), did not have this anticonvulsant effect. In order to explore the basis for the anticonvulsant effect of BDM, we recorded GABA-activated currents (IGABA) of frontal cortical as well as ventromedial hypothalamic neurons before, during and after exposure to this oxime. BDM had a biphasic effect on concentrations (100 μM-40 mM) decreased and lower concentrations (0.01 μM–0.001 μM) potentiatedIGABA; these effects of BDM reversed upon washout of the oxime. In contrast, BTD had no effect onIGABA. Finally, when 0.001 μM BDM, 10–30 μM PTX and GABA were co-applied the inhibitory effect of the toxin onIGABA was markedly suppressed. These data suggest that the anticonvulsant effect of oximes involves facilitation of the inhibitory action of GABA. 相似文献