全文获取类型
收费全文 | 1913篇 |
免费 | 82篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 39篇 |
妇产科学 | 29篇 |
基础医学 | 279篇 |
口腔科学 | 92篇 |
临床医学 | 172篇 |
内科学 | 338篇 |
皮肤病学 | 100篇 |
神经病学 | 176篇 |
特种医学 | 94篇 |
外科学 | 306篇 |
综合类 | 11篇 |
预防医学 | 47篇 |
眼科学 | 96篇 |
药学 | 107篇 |
中国医学 | 4篇 |
肿瘤学 | 112篇 |
出版年
2023年 | 15篇 |
2022年 | 42篇 |
2021年 | 68篇 |
2020年 | 40篇 |
2019年 | 48篇 |
2018年 | 53篇 |
2017年 | 42篇 |
2016年 | 48篇 |
2015年 | 60篇 |
2014年 | 53篇 |
2013年 | 79篇 |
2012年 | 120篇 |
2011年 | 143篇 |
2010年 | 97篇 |
2009年 | 74篇 |
2008年 | 113篇 |
2007年 | 136篇 |
2006年 | 108篇 |
2005年 | 105篇 |
2004年 | 97篇 |
2003年 | 81篇 |
2002年 | 71篇 |
2001年 | 14篇 |
2000年 | 21篇 |
1999年 | 34篇 |
1998年 | 18篇 |
1997年 | 25篇 |
1996年 | 21篇 |
1995年 | 22篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 5篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1969年 | 5篇 |
1968年 | 3篇 |
1967年 | 3篇 |
1966年 | 3篇 |
排序方式: 共有2009条查询结果,搜索用时 15 毫秒
21.
Male chickens from lines divergently selected for fast (FGL) and slow (SGL) growth were compared for the growth of cortical bone. Morphology, histomorphometric, compositional and biomechanical properties of the tibiotarsi were analysed in both lines at 1, 8, 15 and 22 d of age. Tibial morphology (length, volume, cross-section and diameters) was similar in FGL and SGL chickens when compared at an equal body weight. Cortical area was also similar in both lines at an equal body weight but cortex porosity was higher in FGL. Tibial mineral density (ash:volume) was higher in FGL than in SGL at hatching and at 8 d of age. Biomechanical properties were lower in SGL than in FGL at 8 d of age, but then became higher in this line when compared at equal body weight. The very slow growth rate in SGL did not modify bone size when chickens were compared at equal body weight. Bone quality was modified in various ways: in SGL bone structure was strengthened by a lower porosity of the cortex while bone tissue was less mineralized up to 22 d of age. In both lines, cortical growth was slower than in commercial cross-breeds and bone quality (structure and composition) was improved compared to broilers. 相似文献
22.
23.
24.
The phenotypes of the temporomandibular joint (TMJ) disc cells range from fibroblasts to chondrocytes. There are relatively few reported studies using transmission electron microscopy (TEM) to determine the ultrastructural features of these cells. It was hypothesized that at least a subpopulation of TMJ stromal cells could be represented by the telocytes, cells with telopodes. In this regard a TEM study was performed on rat TMJ samples. Collagen-embedded networks were found built-up by cells with telopodes with subplasmalemmal caveolae, moderate content in matrix secretory organelles and well-represented intermediate filaments. Appositions of cell bodies were found. Prolongations of such cells were closely related to nerves and microvessels. Our study indicates that the TMJ disc attachment seems equipped with telocytes capable of stromal signaling. However, further studies are needed to assess whether the telocytes belong to a renewed cell population derived from circulating precursors. 相似文献
25.
Abstract Impending surgery provides a natural stress paradigm within which the effect of stress on cognitive functioning can be assessed. Cardiac patients scheduled for open-heart surgery were tested for cognitive and emotional status on the day before (N = 130) and 7 days after surgery (N = 109). We correlated the self-reported anxiety and depression scores with the performance on 11 neuropsychological tests on both pre-and postoperative examinations. The results indicate that the significantly elevated emotional arousal in these patients has no relevant effect on their cognitive performance. This finding underlines the validity of neuropsychological testing in more acute clinical settings. 相似文献
26.
Annemarie Weissenbacher Honglei Huang Tomas Surik Maria L. Lo Faro Rutger J. Ploeg Constantin C. Coussios Peter J. Friend Benedikt M. Kessler 《American journal of transplantation》2021,21(5):1740-1753
We describe a proteomics analysis to determine the molecular differences between normothermically perfused (normothermic machine perfusion, NMP) human kidneys with urine recirculation (URC) and urine replacement (UR). Proteins were extracted from 16 kidney biopsies with URC (n = 8 donors after brain death [DBD], n = 8 donors after circulatory death [DCD]) and three with UR (n = 2 DBD, n = 1 DCD), followed by quantitative analysis by mass spectrometry. Damage-associated molecular patterns (DAMPs) were decreased in kidney tissue after 6 hours NMP with URC, suggesting reduced inflammation. Vasoconstriction was also attenuated in kidneys with URC as angiotensinogen levels were reduced. Strikingly, kidneys became metabolically active during NMP, which could be enhanced and prolonged by URC. For instance, mitochondrial succinate dehydrogenase enzyme levels as well as carbonic anhydrase were enhanced with URC, contributing to pH stabilization. Levels of cytosolic and the mitochondrial phosphoenolpyruvate carboxykinase were elevated after 24 hours of NMP, more prevalent in DCD than DBD tissue. Key enzymes involved in glucose metabolism were also increased after 12 and 24 hours of NMP with URC, including mitochondrial malate dehydrogenase and glutamic-oxaloacetic transaminase, predominantly in DCD tissue. We conclude that NMP with URC permits prolonged preservation and revitalizes metabolism to possibly better cope with ischemia reperfusion injury in discarded kidneys. 相似文献
27.
28.
Judit Müller Miklós Garami Tamás Constantin Marianne Schmidt György Fekete Gábor Kovács 《Pediatric hematology and oncology》2013,30(4):277-284
The aim of this retrospective study was to evaluate the clinical effectiveness of meropenem in immunocompromised children. Between January 1998 and December 2002 in the hemato-oncological units of our hospital meropenem was used in 87 febrile events diagnosed in 55 patients, and 328 bacterial cultures were evaluated. Microorganisms were detected and identified in 64 of the 328 hemocultures; there was a predominance of gram-positive strains (67%). In 49.4% the infection was documented microbiologically. In 16 additional cases the infection was proven clinically and 32.2% of the episodes were considered to be fever of unknown origin. The success rate of the meropenem therapy—excluding the proven fungal or coagulase-negative Staphylococcus infections—was 72.9% and for the whole cohort 49.4%. The results demonstrate that meropenem is effective and well-tolerated when used for the treatment of neutropenic cancer children. 相似文献
29.
Bradycardia and syncope as manifestations of partial epilepsy 总被引:5,自引:0,他引:5
L Constantin J B Martins R W Fincham R D Dagli 《Journal of the American College of Cardiology》1990,15(4):900-905
Although transient increases in heart rate typically occur, bradycardia has infrequently been noted in association with partial seizures. Five patients with temporal lobe epilepsy are described in whom sinus bradyarrhythmias and syncope were prominent manifestations of seizure activity. Partial improvement occurred in one of two patients in whom a permanent pacemaker was implanted before a diagnosis of epilepsy was established. Treatment with phenytoin or carbamazepine resulted in nearly complete resolution of symptoms in all five patients. Because pacemaker implantation does not prevent recurrent symptoms, but anticonvulsant therapy does, this experience underscores the importance of considering the diagnosis of partial epilepsy in selected patients with sinus bradyarrhythmias and syncope. 相似文献
30.
M G Kienzle J B Martins D J Wendt L Constantin R Hopson M L McCue 《The American journal of cardiology》1988,61(13):1012-1017
Sotalol is a nonselective beta-adrenergic blocking agent with Vaughn-Williams class III activity. Its efficacy was tested in 9 patients with sustained ventricular tachycardia (VT) that had previously remained inducible during electrophysiologic testing of type I drugs (procainamide or quinidine). Eight patients had coronary artery disease with remote myocardial infarction and 1 had cardiomyopathy (ejection fraction 0.34 +/- 0.08, mean +/- standard deviation). Type I drugs prolonged the effective refractory period of the right ventricle 12 +/- 14% and prolonged the VT cycle length 41 +/- 24%. In contrast, despite an equivalent effect on the effective refractory period, a sustained VT could no longer be initiated in any of the 8 patients ultimately tested while taking oral sotalol. Daily doses averaged 600 +/- 103 mg and blood levels associated with VT suppression in electrophysiologic studies were generally greater than 3,000 ng/ml. In addition, sotalol was moderately effective at reducing ventricular ectopic activity measured by ambulatory electrocardiography. Over a mean follow-up of 23 months (range 1 to 37), mild heart failure (3 patients), symptomatic brady-cardia requiring pacemaker (1) and drug-related polymorphous VT (1) have occurred. Sudden death occurred in 1 patient and nonfatal VT recurrence was noted in 2. Five of 8 chronically treated patients currently are successfully treated with minimal side effects. Sotalol appears to be a promising antiarrhythmic drug in the treatment of serious ventricular arrhythmias, even in patients refractory to type I antiarrhythmic agents. 相似文献