全文获取类型
收费全文 | 38059篇 |
免费 | 2803篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 320篇 |
儿科学 | 1001篇 |
妇产科学 | 830篇 |
基础医学 | 6073篇 |
口腔科学 | 731篇 |
临床医学 | 3958篇 |
内科学 | 8190篇 |
皮肤病学 | 781篇 |
神经病学 | 3352篇 |
特种医学 | 1386篇 |
外科学 | 5016篇 |
综合类 | 164篇 |
一般理论 | 21篇 |
预防医学 | 3131篇 |
眼科学 | 478篇 |
药学 | 2744篇 |
中国医学 | 66篇 |
肿瘤学 | 2652篇 |
出版年
2023年 | 386篇 |
2022年 | 138篇 |
2021年 | 513篇 |
2020年 | 564篇 |
2019年 | 665篇 |
2018年 | 1274篇 |
2017年 | 1126篇 |
2016年 | 1111篇 |
2015年 | 977篇 |
2014年 | 1052篇 |
2013年 | 1912篇 |
2012年 | 2861篇 |
2011年 | 2965篇 |
2010年 | 1307篇 |
2009年 | 825篇 |
2008年 | 2485篇 |
2007年 | 2535篇 |
2006年 | 2377篇 |
2005年 | 2212篇 |
2004年 | 2030篇 |
2003年 | 1914篇 |
2002年 | 1844篇 |
2001年 | 969篇 |
2000年 | 1085篇 |
1999年 | 631篇 |
1998年 | 177篇 |
1997年 | 161篇 |
1996年 | 119篇 |
1995年 | 139篇 |
1994年 | 130篇 |
1993年 | 114篇 |
1992年 | 155篇 |
1991年 | 176篇 |
1990年 | 162篇 |
1989年 | 189篇 |
1988年 | 180篇 |
1987年 | 170篇 |
1986年 | 151篇 |
1985年 | 186篇 |
1984年 | 191篇 |
1983年 | 132篇 |
1982年 | 122篇 |
1981年 | 98篇 |
1980年 | 83篇 |
1979年 | 135篇 |
1978年 | 94篇 |
1977年 | 83篇 |
1974年 | 69篇 |
1933年 | 67篇 |
1932年 | 70篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
91.
This paper discusses the use of the Milgram obedience experiments and the Tuskegee syphilis study in the bioethical literature. The two studies are presented and a variety of uses of them identified and discussed. It is argued that the use of these studies as paradigms of problematic research relies on a reduction of their complexity. What is discussed is thus often constructions of these studies that are closer to hypothetical examples than to the real studies. 相似文献
92.
The aim of the study was to determine the role of neurogenic damage to pelvic floor muscles on the outcome of Burch colposuspension. Thirty women objectively continent after Burch colposuspension and 18 women with recurrent stress urinary incontinence (RSUI) were investigated with concentric needle electrode electromyography (EMG) in both pubococcygeus muscles and the external anal sphincter muscle. Neurogenic EMG patterns were significantly more often seen in the pubococcygeus muscles in women with RSUI than in women continent after the colposuspension (P<0.05). The distribution of neurogenic EMG patterns in the investigated muscles was significantly more pronounced in women with RSUI than in continent women: at least one pubococcygeus muscle with neurogenic EMG pattern, 72% vs. 34% (P<0.05); both pubococcygeus muscles, 50% vs. 13% (P<0.05); and all three investigated muscles 41% vs. 10% (P<0.05). In conclusion, the results imply an association between the outcome of the Burch colposuspension and the occurrence of neuropathy in the pelvic floor muscles. Occurrence of neurogenic damage in the pubococcygeus muscles seems to impair the outcome of Burch colposuspension. 相似文献
93.
94.
95.
David G Biron Cécile Joly Laurent Marché Nathalie Galéotti Vincent Calcagno Andreas Schmidt-Rhaesa Lionnel Renault Frédéric Thomas 《Infection, genetics and evolution》2005,5(2):167-175
The proteome of most parasite species is currently unknown. Hairworms (Nematomorpha), 300 species distributed around the world, are parasitic in arthropods (mainly terrestrial species) when juveniles, but they are free-living in aquatic environments when adult. Most aspects of their systematics and biology are currently unknown. The aim of this paper was (i) to report a novel and reproducible protocol for the analysis of the proteome of hairworms using two-dimensional gel electrophoresis (2-DGE) and mass spectrometry (matrix laser desorption ionization-time of flight mass spectrometry (MALDI-TOF)) and (ii) to determine the level of proteomic divergence between two sympatric but taxonomically unrelated nematomorph species in the adult stage, Paragordius tricuspidatus Dufour (Nematomorpha, Gordiidae) and Spinochordodes tellinii Camerano (Nematomorpha, Gordiidae). In total, 689 protein spots were observed for P. tricuspidatus, 575 for S. tellinii. Only 36.2% spots were shared between the two species. Quantitative analysis of the proteins which are common to both parasite species reveals substantial differences in the pattern of protein expression. These results suggest a rapid evolutionary divergence between these two nematomorph families. Also, to test the value of our MALDI-TOF protocol, we used Actin-2 (Act-2), a protein highly conserved in the course of evolution. Peptide mass fingerprint (PMF) data obtained for Act-2 of P. tricuspidatus and S. tellinii suggest a very high homology with Act-2 of different worms species belonging to the Bilateria phylum (Annelida and Nematoda) and more specifically to Lumbricus terrestris (Annelida, Lumbricidae) and Caenorhabditis elegans (Nematoda, Rhabditidae). We discuss our results in relationship with current ideas concerning the use of proteomics in systematics. 相似文献
96.
Baseline heart rate may predict hypotension after spinal anesthesia in prehydrated obstetrical patients 总被引:3,自引:0,他引:3
PURPOSE: Hypotension is the most frequent complication of spinal anesthesia in pregnant patients. This study was designed to identify patients at risk for postspinal hypotension based on preoperative vital signs before and after an orthostatic challenge. METHODS: Forty healthy women scheduled for elective Cesarean section were enrolled in this prospective trial. Blood pressure (BP) and heart rate (HR) were recorded with the patient in the lateral supine position and after standing up. After a bupivacaine spinal anesthetic, BP was obtained every two minutes for 30 min. Ephedrine treatment was administered based on the degree of hypotension observed. Hemodynamic parameters were correlated to ephedrine requirements (Spearman's rank order correlation). RESULTS: There was a significant correlation in baseline maternal HR and ephedrine requirements (P=0.005). The degree of orthostatic changes in mean arterial BP and HR did not correlate with postspinal hypotension. CONCLUSIONS: Baseline HR may be predictive of obstetric spinal hypotension. Higher baseline HR, possibly reflecting a higher sympathetic tone, may be a useful parameter to predict postspinal hypotension. 相似文献
97.
Intra-observer and inter-observer agreement of the manual examination of the lumbar spine in chronic low-back pain 总被引:1,自引:1,他引:0
Etienne Qvistgaard Jens Rasmussen Jes Lætgaard Steen Hecksher-Sørensen Henning Bliddal 《European spine journal》2007,16(2):277-282
Examination is a cornerstone in the manual procedures leading to mobilisation/manipulation of the low back. The observer variation of the more specific segmental tests remains to be investigated. Two skilled specialists in manual medicine examined the segmental changes in the lumbar spine. The patients were unknown to the examiners and no information of the case history was given. All test results were recorded by an observer present in the room who ensured that no conversation was allowed during the examination. The primary outcome measures were the kappa values for each test. The matching was defined as acceptable (acc) within two neighbouring levels and perfect (per) on the same level. Intra-observer variation (tested in 33 patients and 10 subjects without low-back pain): The agreement between first and second segmental diagnosis examination was 70% (per) and 82% (per + acc). Kappa values were: segmental diagnosis 0.60 (per) and 0.70 (per + acc), multifidus test 0.51 (per) and 0.60 (per + acc), sideflexion 0.57 (per) and 0.69 (per + acc), and ventral flexion 0.31 (per) and 0.45 (per + acc). Inter-observer variation (tested in 60 patients): The agreement for segmental diagnosis between the examiner A and B was 42% (per) and 75% (per + acc). Kappa values were: segmental diagnosis 0.21 (per) and 0.57 (acc), multifidus test 0.12 (per) and 0.48 (acc), sideflexion 0.22 (per) and 0.45 (acc), and ventralflexion 0.22 (per) and 0.44 (acc). By manual tests, skilled examiners seem to be able to diagnose segmental dysfunctions in the low back. The clinical implication of these dysfunctions remains to be clarified. 相似文献
98.
99.
100.