全文获取类型
收费全文 | 6286篇 |
免费 | 411篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 127篇 |
妇产科学 | 80篇 |
基础医学 | 731篇 |
口腔科学 | 124篇 |
临床医学 | 564篇 |
内科学 | 1553篇 |
皮肤病学 | 166篇 |
神经病学 | 831篇 |
特种医学 | 185篇 |
外科学 | 1046篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 253篇 |
眼科学 | 80篇 |
药学 | 554篇 |
中国医学 | 8篇 |
肿瘤学 | 368篇 |
出版年
2024年 | 6篇 |
2023年 | 60篇 |
2022年 | 143篇 |
2021年 | 222篇 |
2020年 | 113篇 |
2019年 | 179篇 |
2018年 | 225篇 |
2017年 | 160篇 |
2016年 | 189篇 |
2015年 | 189篇 |
2014年 | 263篇 |
2013年 | 316篇 |
2012年 | 441篇 |
2011年 | 450篇 |
2010年 | 260篇 |
2009年 | 264篇 |
2008年 | 399篇 |
2007年 | 382篇 |
2006年 | 379篇 |
2005年 | 385篇 |
2004年 | 351篇 |
2003年 | 311篇 |
2002年 | 264篇 |
2001年 | 54篇 |
2000年 | 61篇 |
1999年 | 55篇 |
1998年 | 64篇 |
1997年 | 38篇 |
1996年 | 44篇 |
1995年 | 28篇 |
1994年 | 44篇 |
1993年 | 23篇 |
1992年 | 37篇 |
1991年 | 39篇 |
1990年 | 37篇 |
1989年 | 45篇 |
1988年 | 27篇 |
1987年 | 17篇 |
1986年 | 26篇 |
1985年 | 24篇 |
1984年 | 26篇 |
1983年 | 19篇 |
1982年 | 8篇 |
1981年 | 14篇 |
1980年 | 10篇 |
1979年 | 13篇 |
1976年 | 7篇 |
1973年 | 4篇 |
1968年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有6741条查询结果,搜索用时 15 毫秒
11.
Kallol Ray Chaudhuri Pablo Martinez-Martin Anthony H V Schapira Fabrizio Stocchi Kapil Sethi Per Odin Richard G Brown William Koller Paolo Barone Graeme MacPhee Linda Kelly Martin Rabey Doug MacMahon Sue Thomas William Ondo David Rye Alison Forbes Susanne Tluk Vandana Dhawan Annette Bowron Adrian J Williams Charles W Olanow 《Movement disorders》2006,21(7):916-923
Nonmotor symptoms (NMS) of Parkinson's disease (PD) are not well recognized in clinical practice, either in primary or in secondary care, and are frequently missed during routine consultations. There is no single instrument (questionnaire or scale) that enables a comprehensive assessment of the range of NMS in PD both for the identification of problems and for the measurement of outcome. Against this background, a multidisciplinary group of experts, including patient group representatives, has developed an NMS screening questionnaire comprising 30 items. This instrument does not provide an overall score of disability and is not a graded or rating instrument. Instead, it is a screening tool designed to draw attention to the presence of NMS and initiate further investigation. In this article, we present the results from an international pilot study assessing feasibility, validity, and acceptability of a nonmotor questionnaire (NMSQuest). Data from 123 PD patients and 96 controls were analyzed. NMS were highly significantly more prevalent in PD compared to controls (PD NMS, median = 9.0, mean = 9.5 vs. control NMS, median = 5.5, mean = 4.0; Mann-Whitney, Kruskal-Wallis, and t test, P < 0.0001), with PD patients reporting at least 10 different NMS on average per patient. In PD, NMS were highly significantly more prevalent across all disease stages and the number of symptoms correlated significantly with advancing disease and duration of disease. Furthermore, frequently, problems such as diplopia, dribbling, apathy, blues, taste and smell problems were never previously disclosed to the health professionals. 相似文献
12.
G Clementi M Grassi C Valerio A Prato C E Fiore F Drago 《Pharmacology, biochemistry, and behavior》1992,42(3):545-548
The effects of central administration of calcitonin gene-related peptide (CGRP, 1 or 100 ng/rat) on behavioral and biochemical parameters related to the extrapyramidal motor system were investigated in male rats. The peptide-induced catalepsy occurred only at the dose of 100 ng/rat and hypomotility at both doses used. Calcitonin gene-related peptide increased haloperidol-induced catalepsy and decreased apomorphine-induced hypermotility at the doses of 1 and 100 ng/rat. Although these behaviors are related to dopamine, no significant change of striatal DA or DOPAC concentration were observed after central administration of the peptide. Other neurotransmitters may be directly or indirectly involved in these behavioral effects of CGRP. 相似文献
13.
14.
15.
16.
Ruggero de Paulis Fabrizio Tomai Fabio Bertoldo Anna S Ghini Raffaele Scaffa Paolo Nardi Luigi Chiariello 《European journal of cardio-thoracic surgery》2004,26(1):66-72
OBJECTIVES: The sinuses of Valsalva are known to contribute to the normal function of the aortic valve. Little is known about their role in promoting coronary artery blood flow. The aim of this study was to compare coronary artery flow characteristics among patients undergoing a Bentall operation by means of a conventional cylindrical Dacron conduit or with a new conduit with pseudosinuses of Valsalva or in patients retaining their natural sinuses of Valsalva after aortic valve and supracoronary ascending aorta replacement. METHODS: One year after a Bentall procedure with a standard cylindrical Dacron conduit (7 patients, group A) or with the new conduit (7 patients, group B), or after aortic valve and ascending aortic replacement (control group, 7 patients, group C) coronary flow velocity reserve and diastolic to systolic time integral ratio at baseline and after maximal hyperemia (with 40 microg of adenosine) were assessed by using a 0.014-in. Doppler guidewire positioned in the middle portion of the left anterior descending coronary artery. All patients were in NYHA class I, sinus rhythm and free of coronary disease. RESULTS: Arterial blood pressures and heart rate were comparable among groups. Intracoronary Doppler measurements did not show any significant difference in coronary vascular reserve between the three groups (3.6+/-0.4 vs 3.1+/-0.7 vs 3.7+/-0.5, P = 0.2). A greater diastolic component at baseline was present in group B patients (5.5+/-1.9 vs 3.5+/-0.9 in group A and 3.7+/-0.9 in group C, P = 0.024). After maximal hyperemia the diastolic component increased slightly in group A patients (8%) while both in groups B and C significantly decreased (-15 and -20%, respectively) (P = 0.017). CONCLUSIONS: The presence of pseudosinuses of Valsalva does not influence coronary flow reserve. After maximal coronary vasodilation the increase in the systolic component of coronary flow is more evident in the presence of sinuses or pseudosinuses of Valsalva, thus suggesting that coronary flow pattern may be affected by the presence of sinuses. 相似文献
17.
Michael B. Farnell Gerard V. Aranha Yuji Nimura Fabrizio Michelassi 《Journal of gastrointestinal surgery》2008,12(4):651-656
With improvements in the safety of Whipple resection in recent decades, surgeons have continued to explore the role of more
extensive lymphadenectomy in hope of improving long-term survival. A systematic literature search of level I evidence addressing
the role of the extent of lymphadenectomy was undertaken. Only reports of prospective, randomized controlled trials comparing
pancreaticoduodenectomy with standard lymphadenectomy to pancreaticoduodenectomy with extended lymphadenectomy where information
regarding survival, morbidity, mortality, the number of resected lymph nodes in each group and detailed operative technique
were included. Four prospective, randomized trials comprising some 424 patients and one meta-analysis were identified. In
aggregate, these studies confirmed that the number of resected lymph nodes was significantly higher in the pancreaticoduodenectomy
with extended lymphadenectomy group. Morbidity and mortality rates were comparable. Postoperative diarrhea in the early months
after operation was problematic in patients undergoing extended lymphadenectomy. In none of the studies was a benefit in long-term
survival demonstrated. Standard pancreaticoduodenectomy continues to be the operation of choice for adenocarcinoma of the
head of the pancreas.
Presented at The Society for Surgery of the Alimentary Tract Postgraduate Course “Systematic Reviews of Pancreaticobiliary
Disease Customized for the Gastroenterologist and Gastrointestinal Surgeon” on May 20, 2007, Washington, D.C. 相似文献
18.
In recent years, a growing interest in the study of peptide antigenicity in relation to the role of flanking sequences and protein topology in processing, presentation, and recognition has been observed. However, the information available on the antigenicity of recombinant fusion proteins and their effect on the selection of antigen receptor repertoires is limited. To analyze the role of molecular topology of T epitopes in a system relevant to human pathology, we have used the bacterially expressed Schistosoma japonicum glutathione S transferase (GST) to construct recombinant antigens containing HIV-1 derived T cell determinants, and human T cell clones specific for these determinants. We found that antigenicity of a given GST—peptide combination was not the same when T cells and antigen presenting cells from different individuals were tested. Our results show that differences in processing and presentation of chimeric proteins are not dictated by the use of diverse restriction elements. We also found that the context in which an antigenic peptide is delivered affects the recruited repertoire as defined according to T cell receptor Vβ usage and fine specificities of selected T cells. 相似文献
19.
Summary Human fibrin glue (Tissucol) is a plasma-derived compound endowed with adhesive and hemostatic properties and possessing a specific local anti-infection function mediated through activation of nonspecific immunity elements. The aim of this study is to show that in patients who have undergone prolonged reconstructive plastic surgery following cancer resection, Tissucol decreases infectious complications as compared to a control group. Between June 1985 and February 1988, 51 subjects were treated with fibrin glue during reconstruction operations. Analysis of the results showed that Tissucol produced a statistically significant reduction both of immediate complications, such as inflammation and partial separation of the surgical wound, and of delayed complications, such as scar hypertrophy and cutaneous fistulae. In conclusion, patients treated with Tissucol showed a better quality of surgical wound, a more rapid postoperative functional recovery and consequently a decrease in the duration of hospitalization. 相似文献
20.
Effect of excimer laser on microbiological organisms 总被引:2,自引:0,他引:2
The effect of radiation emitted from an excimer laser filled with argon fluoride gas at 193 nm on Serratia marcescens, Pseudomonas aeruginosa, Staphylococcus aureus, streptococcus faecalis, Hemophilus influenzae, Candida albicans, and Aspergillus niger (collectively labeled "the microorganisms") was examined. Colonies were subjected to a variable number of radiation pulses from the excimer laser applied after a 36-hour period of incubation at 37 degrees C, at which time the colonies were fully grown and showed no viability. The lack of viability was confirmed with a subculture from each area that received radiation; all subcultures were negative. The characteristics of the radiation paralleled those used by Serdavic, Darrell, Krueger, et al in 1985.(1) This radiation treatment is believed to be within a therapeutic range, which suggests that the excimer laser, pending further investigation, may be useful in the treatment of corneal infections. 相似文献