全文获取类型
收费全文 | 40659篇 |
免费 | 2210篇 |
国内免费 | 130篇 |
专业分类
耳鼻咽喉 | 410篇 |
儿科学 | 1231篇 |
妇产科学 | 889篇 |
基础医学 | 6199篇 |
口腔科学 | 323篇 |
临床医学 | 3830篇 |
内科学 | 9710篇 |
皮肤病学 | 877篇 |
神经病学 | 3688篇 |
特种医学 | 1328篇 |
外国民族医学 | 31篇 |
外科学 | 4920篇 |
综合类 | 151篇 |
一般理论 | 6篇 |
预防医学 | 2834篇 |
眼科学 | 646篇 |
药学 | 2781篇 |
中国医学 | 78篇 |
肿瘤学 | 3067篇 |
出版年
2023年 | 219篇 |
2022年 | 162篇 |
2021年 | 589篇 |
2020年 | 348篇 |
2019年 | 642篇 |
2018年 | 1172篇 |
2017年 | 806篇 |
2016年 | 761篇 |
2015年 | 956篇 |
2014年 | 985篇 |
2013年 | 1606篇 |
2012年 | 2739篇 |
2011年 | 2679篇 |
2010年 | 1327篇 |
2009年 | 1094篇 |
2008年 | 2441篇 |
2007年 | 2540篇 |
2006年 | 2357篇 |
2005年 | 2461篇 |
2004年 | 2384篇 |
2003年 | 2163篇 |
2002年 | 2108篇 |
2001年 | 1114篇 |
2000年 | 1179篇 |
1999年 | 949篇 |
1998年 | 242篇 |
1997年 | 186篇 |
1996年 | 180篇 |
1995年 | 162篇 |
1994年 | 132篇 |
1993年 | 118篇 |
1992年 | 552篇 |
1991年 | 487篇 |
1990年 | 499篇 |
1989年 | 481篇 |
1988年 | 441篇 |
1987年 | 419篇 |
1986年 | 377篇 |
1985年 | 346篇 |
1984年 | 242篇 |
1983年 | 207篇 |
1982年 | 117篇 |
1979年 | 170篇 |
1974年 | 132篇 |
1973年 | 117篇 |
1972年 | 121篇 |
1971年 | 130篇 |
1970年 | 115篇 |
1969年 | 141篇 |
1968年 | 125篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
J P Becquemin E Paris A Valverde F Pluskwa D Mellière 《The Journal of cardiovascular surgery》1991,32(5):592-598
We retrospectively studied a series of 385 carotid endarterectomies performed either under general anesthesia (242) or under local anesthesia (145) to compare the peri-operative mortality and morbidity rate and to identify factors which may influence the choice of anesthesia. The rate of transient ischaemic attacks (TIA), stroke, death, combined mortality, severe neurological and cardiac morbidity were not statistically different. Under general anesthesia, more shunts were inserted (17% versus 7%, p less than 0.05) and more myocardial infarctions occurred (5% versus 0%, p less than 0.05). However, more strokes due to technical imperfection were seen under regional anesthesia. We concluded that regional anesthesia is more appropriate in patients with coronary artery disease and in patients at risk of intolerance to cross clamping. General anesthesia is more appropriate in poorly cooperative patients or in those with unfavorable operative conditions. 相似文献
62.
Sandrine Péroche Ghania Degobert Jean-Luc Putaux Marie-Geneviève Blanchin Hatem Fessi Hélène Parrot-Lopez 《European journal of pharmaceutics and biopharmaceutics》2005,60(1):123-131
This work describes the synthesis of new amphiphilic perfluorohexyl- and perfluorooctyl-propanethio-beta-cyclodextrins and the comparison of the ability of these molecules and alkyl analogue, nonanethio-beta-cyclodextrin to form nanospheres. Nanospheres were prepared using nanoprecipitation method (perfluoroalkylthio-beta-cyclodextrin in THF [0.11 x 10(-3)M], stirring rate 700rpm, addition of aqueous phase at 64 degrees C into organic phase at 50 degrees C). They were characterised by Photon Correlation Spectroscopy (PCS) and by electron microscopy (SEM and cryo-TEM). The nanospheres prepared from these new beta-cyclodextrin derivatives have an average size of 260nm, and appear to be spherical in cryo-TEM images. Whereas alkyl analogue forms polydisperse aggregates with sizes in the range 60-350nm. 相似文献
63.
64.
There is an inverse relationship between Mg balance and the ratio ionized Mg/total Mg in serum or plasma: in Mg excess, the ratio is decreased and in Mg deficiency the ratio is increased. It works as if a subtle homeostasic compensatory reaction modified the proportion of the most biologically active fraction of blood Mg in order to reduce the effects of Mg imbalance. Easy, available and unexpensive, the evaluation of total Mg in plasma or serum appears as a better marker than ionized Mg in Mg imbalance: it should be priviledged as the initial investigation in clinical practice. 相似文献
65.
Véronique Strijckmans Michel Bottlaender Humin Luo Michèle Ottavianil Daniel W. McPherson Christian Loc'h Chantal Fuseau Furn F. Knapp Bernard Mazière 《European journal of nuclear medicine and molecular imaging》1997,24(5):475-482
We studied the potential of three radiobrominated isomers of BrQNP, (Z(-,-)-[76Br]BrQNP,E(-,-)-[76Br]BrQNP andE(-,+)-[76Br]BrQNP), as suitable radioligands for imaging of central muscarinic cholinergic receptors in the human brain. These radioligands were stereospecifically prepared by electrophilic radiobromodestannylation of the respective tributylstannyl precursors using no-carrier-added [76Br]BrNH4 and peracetic acid. Preliminary pharmacological characterizations were determined by biodistribution, autoradiography, competition, displacement and metabolite studies in rats. The (-,-)-configuration presented important specific uptakes in brain muscarinic cholinergic receptor (mAChR)-rich structures and in heart, low metabolization rates and an apparent M2 selectivity. The (-,+)-configuration revealed more rapid clearance, lower uptake, a higher metabolization rate and an apparent M1 selectivity. Reversibility of the binding was confirmed for the three radiotracers. Positron emission tomography in the living baboon brain revealed high and rapid uptake in the brain and accumulation in the mAChR-rich structures studied. At 30 min p.i., theE(-,-)-radiotracer reached a plateau in cortex, pons and thalamus with concentrations of 29%, 24% and 19% ID/l, respectively.Z(-,-)-[76Br]BrQNP also accumulated in these structures, reaching a maximal uptake (27% ID/l) in the cortex 2 h p.i. At 5 min p.i. a plateau (17% ID/l) was only observed in the cortex for theE(-,+)-[76Br]BrQNP; by contrast, the other structures showed slow washout. After 3 weeks, the (-,-)-radiotracers were studied in the same baboon pretreated with dexetimide (1 mg/kg), a well-known muscarinic antagonist. In all the mAChR structures, the highly reduced uptake observed after this preloading step indicates that these radiotracers specifically bind to muscarinic receptors.Z(-,-)-[76Br]BrQNP, which is displaced in higher amounts from M2 mAChR-enriched structures, reveals an M2 affinity. The two isomers having the (-,-)-configuration are potential probes for investigating central muscarinic receptors. The absolute configuration on the acetate chiral centre influences their muscarinic subtype selectivity and thecis-trans isomerism of the vinyl moiety affects their specific fixation. 相似文献
66.
C. H. van der Meyden J. F. K. de Villiers B. D. Middlecote J. Terblanchè 《Neuroradiology》1994,36(3):221-223
A 9-year-old boy presented with a subacute history of optic neuritis followed by brainstem involvement, with fever and a lymphocytic pleocytosis in the cerebrospinal fluid. Gadolinium-enhancing ring lesions were demonstrate in the white matter of the cerebrum, brainstem and cerebellum on day 17 of the illness, all appearing simultaneously as part of a monophasic illness. A parietal lesion exerted mass effect. Needling and biopsy yielded no evidence of a pyogenic lesion, tumour or tuberculosis and showed vasculitis. There was insufficient material for myelin staining. Dexamethasone therapy lead to rapid improvement of the radiological lesions: MRI and CT on day 34 of the illness showed complete clearing of the lesions except for residual abnormality at the biopsy site. 相似文献
67.
D Labbé E Kaluzinski J Y Ferrand A Dompmartin J F Compère 《Revue de stomatologie et de chirurgie maxillo-faciale》1991,92(6):402-405
After briefly summing up the nosology of rhinophyma, the authors report their experience with the surgical correction of this nasal disease, on the basis of eight cases. They explain their reasons for giving up dermasection and preferring dermabrasion. 相似文献
68.
69.
70.