全文获取类型
收费全文 | 279706篇 |
免费 | 20070篇 |
国内免费 | 1209篇 |
专业分类
耳鼻咽喉 | 2996篇 |
儿科学 | 7190篇 |
妇产科学 | 5221篇 |
基础医学 | 36814篇 |
口腔科学 | 4939篇 |
临床医学 | 28265篇 |
内科学 | 58949篇 |
皮肤病学 | 3681篇 |
神经病学 | 26963篇 |
特种医学 | 9093篇 |
外国民族医学 | 14篇 |
外科学 | 42103篇 |
综合类 | 4043篇 |
一般理论 | 357篇 |
预防医学 | 24105篇 |
眼科学 | 7478篇 |
药学 | 19187篇 |
6篇 | |
中国医学 | 397篇 |
肿瘤学 | 19184篇 |
出版年
2023年 | 1499篇 |
2022年 | 2647篇 |
2021年 | 6007篇 |
2020年 | 3624篇 |
2019年 | 5890篇 |
2018年 | 6544篇 |
2017年 | 4929篇 |
2016年 | 5532篇 |
2015年 | 6452篇 |
2014年 | 9494篇 |
2013年 | 13158篇 |
2012年 | 19880篇 |
2011年 | 20824篇 |
2010年 | 11724篇 |
2009年 | 10416篇 |
2008年 | 18228篇 |
2007年 | 19201篇 |
2006年 | 19147篇 |
2005年 | 19096篇 |
2004年 | 17952篇 |
2003年 | 16592篇 |
2002年 | 15510篇 |
2001年 | 2417篇 |
2000年 | 1884篇 |
1999年 | 2622篇 |
1998年 | 3417篇 |
1997年 | 2857篇 |
1996年 | 2456篇 |
1995年 | 2360篇 |
1994年 | 1972篇 |
1993年 | 1793篇 |
1992年 | 1484篇 |
1991年 | 1345篇 |
1990年 | 1180篇 |
1989年 | 1129篇 |
1988年 | 1152篇 |
1987年 | 1084篇 |
1986年 | 1094篇 |
1985年 | 1098篇 |
1984年 | 1364篇 |
1983年 | 1271篇 |
1982年 | 1513篇 |
1981年 | 1463篇 |
1980年 | 1252篇 |
1979年 | 794篇 |
1978年 | 830篇 |
1977年 | 726篇 |
1976年 | 674篇 |
1975年 | 549篇 |
1974年 | 573篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Dr. Robert L. Geggel David R. Fulton Harvey L. Chernoff Richard Cleveland Thomas J. Hougen 《Pediatric cardiology》1987,8(4):279-283
Summary An infant girl is described who had cor triatriatum and partial anomalous pulmonary venous connection of the left pulmonary
veins to the coronary sinus, the first report of this combination of lesions. The infant also had a Dandy-Walker malformation
and multiple facial and intrathoracic hemangiomas. The cardiac diagnosis was made by two-dimensional echocardiography. Cardiac
catheterization and angiography confirmed the findings and also demonstrated a persistent left superior vena cava draining
to the coronary sinus. The infant underwent successful surgical repair. Partial anomalous pulmonary venous connection and
left superior vena cava not infrequently are associated with cor triatriatum. Although two-dimensional echocardiography is
sensitive for the detection of cor triatriatum, preoperative cardiac catheterization is necessary to identify unequivocally
systemic and pulmonary venous connections. 相似文献
62.
RenNew-D (Alcide), a novel demand-release sporocidal agent, was employed instead of formaldehyde in the reprocessing for reuse of cuprophan hollow fiber dialyzers (Gambro) and the performance of these dialyzers was evaluated over 40 consecutive dialyses in six patients on maintenance hemodialysis. When RenNew-D was part of automated reprocessing performed with 4.3% bleach as specified by the manufacturer (Lixivitron), dialyzer survival was prolonged (16.7 +/- 7.2 uses) and hemodialysis neutropenia was unchanged with reuse. When RenNew-D was part of manual reprocessing conducted in the absence of bleach, marked improvement in dialyzer biocompatibility was observed but with a decreased survival (4.8 +/- 3.0). The majority of dialyzer failures were due to a fall in fiber bundle volume below a 85% set limit. Small solute clearances were maintained with both types of reprocessing. Dialyses were well tolerated throughout. Our data suggest that RenNew-D is a safe and efficacious product which can serve as a valuable alternative to formaldehyde for the purpose of dialyzer reuse. 相似文献
63.
64.
Lucy Yardley David Papo Adolfo Bronstein Michael Gresty Mark Gardner Nilli Lavie Linda Luxon 《Neuropsychologia》2002,40(4):373-383
The aim of this series of experiments was to determine whether attention is normally required for continuously processing vestibular information concerning orientation, or is required only when orientation is disrupted (eg by vestibular dysfunction or by conflicting visual and vestibular orientation cues). In the first two studies, healthy subjects were passively oscillated, and indicated when they perceived they were passing through their starting position. There was only weak evidence for interference between performance on this 'continuous orientation monitoring task' and on concurrent mental tasks. However, a third study showed that when patients with vestibular imbalance carried out the continuous orientation monitoring task their performance on a concurrent mental arithmetic task was substantially impaired. This dual task interference was correlated with inaccuracy in judging orientation on the continuous orientation monitoring task, which in turn correlated with severity of recent vestibular symptomatology (assessed by questionnaire). In a fourth experiment, disorientation was induced in healthy subjects by rotating the visual field about the line of sight. Bidirectional interference was observed between monitoring orientation (assessed by accuracy in setting a rod to the perceived vertical) and performance of an arithmetic task. Dual task interference was correlated with baseline levels of disorientation induced by the visual field, as indicated by inaccuracy in judging the visual vertical. These findings suggest that monitoring orientation makes significant demands upon cortical processing resources when disorientation is induced, whether the disorientation results from deficient sensory functioning or from ambiguous perceptual information. 相似文献
65.
The efficacy of radiology in evaluating dysphagia was studied in 86 patients by comparison to endoscopic findings. In the 66 patients with endoscopic abnormalities radiology was correct in 54, for a sensitivity of 82%. Sensitivity of radiology improved to 95% if mild esophagitis was excluded. In the 20 patients with normal endoscopy, radiology was normal in 18 (90%). Thus radiology proved to be a reliable means of evaluating the esophagus in patients with dysphagia. 相似文献
66.
Peter D. Le Roux David S. Jardine Paul M. Kanev John D. Loeser 《Child's nervous system》1991,7(1):34-39
We reviewed the results of all pediatric patients undergoing intracranial pressure (ICP) monitoring in a 2-year period at our institution. The outcome of patients suffering hypoxia or ischemic injuries (HII) is compared to those suffering non-hypoxic or non-ischemic injuries (NHII). Thirty-four patients had ICP monitors placed during the study period. Inconplete patient information led to the exclusion of 5 patients. An additional 5 patients were excluded because no measures to control ICP were taken after the monitor was placed. Twenty-four patients required treatment for raised ICP (hyperventilation, 24; mannitol, 19; barbiturate coma, 6). Admission Glasgow Coma Score in patients suffering HII (median score 5) and NHII (median score 6) were not significantly different (Mann-Whitney U Test). Only 2 of 8 patients with HII were near-drowning vietims. The remaining 6 had HII from other causes (5 survivors of various forms of asphyxia and 1 of cardiac arrest). All 8 patients had poor outcomes (1 severely disabled; 7 died). The 16 patients with NHII had a variety of diagnoses (6 trauma, 5 encephalitis, 4 bacterial meningitis, 1 diabetic ketoacidosis). Among these, 6 had good outcomes and 10 poor outcomes (2 severely disabled, 2 vegetative, and 6 died). The difference in outcome between patients with NHII and HII is significant at P=0.059 (Fischer Exact test). Patients with NHII may benefit from ICP monitoring. Patients with HII from near-drowning and other causes did not appear to benefit from ICP monitoring and interventions directed at controlling ICP. 相似文献
67.
68.
69.
Michael S Benninger Peter C Appelbaum James C Denneny David J Osguthorpe James A Stankiewicz 《Otolaryngology--head and neck surgery》2002,127(1):7-12
OBJECTIVE: Traditional assessments of the microbial flora associated with acute bacterial rhinosinusitis have relied on maxillary sinus punctures (taps) and culture. These taps are now considered the gold standard for obtaining cultures and are used as the method of identifying bacterial pathogens in antimicrobial trials. Maxillary sinus taps are limited by discomfort to the patients and technical concerns. Because of these factors, the standard of performing taps has limited antibiotic trials and microbial surveillance. Alternatives to maxillary sinus taps have been explored. STUDY DESIGN: We conducted a retrospective, systematic review of the literature from 1950 to 2000 of articles comparing culture techniques in the nose and paranasal sinuses for acute bacterial rhinosinusitis. RESULTS: Nasal cultures have poor correlation to maxillary sinus cultures, whereas there is 60% to 85% concordance between endoscopically guided middle meatal cultures and maxillary sinus cultures. These studies, however, are all limited by small sample sizes and therefore are inadequate to make any concrete recommendations regarding the relative role of endoscopically guided middle meatal cultures as a formal method of pathogen identification in acute bacterial rhinosinusitis. CONCLUSION: A formal prospective study with sufficient sample size to assess the concordance between the microbial flora of the maxillary sinus punctures and middle meatal cultures in acute rhinosinusitis is recommended. 相似文献
70.
Geert Verreck Annelies Decorte Koen Heymans Jef Adriaensen Dirk Cleeren Adri Jacobs Dehua Liu David Tomasko Albertina Arien Jef Peeters Patrick Rombaut Guy Van den Mooter Marcus E Brewster 《European journal of pharmaceutical sciences》2005,26(3-4):349-358
The aim of the current research project was to explore the possibilities of combining pressurized carbon dioxide with hot stage extrusion during manufacturing of solid dispersions of itraconazole and polyvinylpyrrolidone-co-vinyl acetate 64 (PVP-VA 64) and to evaluate the ability of the pressurized gas to act as a temporary plasticizer as well as to produce a foamed extrudate. Pressurized carbon dioxide was injected into a Leistritz Micro 18 intermeshing co-rotating twin-screw melt extruder using an ISCO 260D syringe pump. The physicochemical characteristics of the extrudates with and without injection of carbon dioxide were evaluated with reference to the morphology of the solid dispersion and dissolution behaviour and particle properties. Carbon dioxide acted as plasticizer for itraconazole/PVP-VA 64, reducing the processing temperature during the hot stage extrusion process. Amorphous dispersions were obtained and the solid dispersion was not influenced by the carbon dioxide. Release of itraconazole from the solid dispersion could be controlled as a function of processing temperature and pressure. The macroscopic morphology changed to a foam-like structure due to expansion of the carbon dioxide at the extrusion die. This resulted in increased specific surface area, porosity, hygroscopicity and improved milling efficiency. 相似文献