全文获取类型
收费全文 | 4669篇 |
免费 | 283篇 |
国内免费 | 52篇 |
专业分类
耳鼻咽喉 | 66篇 |
儿科学 | 74篇 |
妇产科学 | 73篇 |
基础医学 | 575篇 |
口腔科学 | 78篇 |
临床医学 | 407篇 |
内科学 | 1393篇 |
皮肤病学 | 95篇 |
神经病学 | 395篇 |
特种医学 | 183篇 |
外科学 | 706篇 |
综合类 | 25篇 |
一般理论 | 5篇 |
预防医学 | 189篇 |
眼科学 | 58篇 |
药学 | 264篇 |
中国医学 | 9篇 |
肿瘤学 | 409篇 |
出版年
2024年 | 9篇 |
2023年 | 48篇 |
2022年 | 75篇 |
2021年 | 177篇 |
2020年 | 98篇 |
2019年 | 147篇 |
2018年 | 161篇 |
2017年 | 121篇 |
2016年 | 146篇 |
2015年 | 154篇 |
2014年 | 185篇 |
2013年 | 275篇 |
2012年 | 443篇 |
2011年 | 386篇 |
2010年 | 219篇 |
2009年 | 174篇 |
2008年 | 317篇 |
2007年 | 272篇 |
2006年 | 262篇 |
2005年 | 265篇 |
2004年 | 233篇 |
2003年 | 197篇 |
2002年 | 185篇 |
2001年 | 48篇 |
2000年 | 39篇 |
1999年 | 43篇 |
1998年 | 35篇 |
1997年 | 19篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 20篇 |
1993年 | 11篇 |
1992年 | 15篇 |
1991年 | 16篇 |
1990年 | 20篇 |
1989年 | 14篇 |
1988年 | 19篇 |
1987年 | 16篇 |
1986年 | 20篇 |
1985年 | 16篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1979年 | 16篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1974年 | 3篇 |
1971年 | 3篇 |
排序方式: 共有5004条查询结果,搜索用时 109 毫秒
11.
Giulio Balbontin Dario Dainelli Maurizio Galimberti Guglielmo Paganetto 《Macromolecular chemistry and physics.》1992,193(3):693-703
Thermal characterization was carried out on highly stereoregular and regioregular syndiotactic polypropene (sPP) obtained with isopropylidene(cyclopentadienyl)(9-fluorenyl)zirconium dichloride and methylaluminoxane. The influence of molecular weight and syndiotacticity degree on the thermodynamic melting point (T°m) of sPP were separately investigated by examining samples with a fully syndiotactic pentads content (rrrr) ranging from ca. 81% to ca. 94% and with an weight-average molecular weight (M?w) ranging from 9,6 · 104 to 17,3 · 104. Upon excluding any influence of the molecular weight, the correlation between the rrrr pentads content and the T°m of the samples led to the extrapolation of the thermodynamic melting point for a fully syndiotactic polypropene. 相似文献
12.
13.
Tobias von Lukowicz Michela Silacci Matthias T Wyss Eveline Trachsel Christine Lohmann Alfred Buck Thomas F Lüscher Dario Neri Christian M Matter 《Journal of nuclear medicine》2007,48(4):582-587
Targeting proteins that are overexpressed in atherosclerotic plaques may open novel diagnostic applications. The C domain of tenascin-C is absent from normal adult tissues but can be inserted during tumor progression or tissue repair into the molecule by alternative splicing. We tested the ability of the human antibody G11, specific to this antigen, to reveal murine atherosclerotic plaques ex vivo. The antibody directed against the extra domain B of fibronectin (L19) was used as a reference. METHODS: We intravenously injected (125)I-labeled G11 or L19 antibodies into apolipoprotein E-deficient (ApoE(-/-)) mice and harvested the aortae 4 or 24 h later. En face analyses of distal aortae and longitudinal sections of the aortic arch were performed to compare antibody uptake using autoradiography with plaque staining using oil red O. Plaque macrophages were detected by immunohistochemistry (anti-CD68 staining). Biodistribution of injected antibodies was investigated in aortae and blood at 4 and 24 h. RESULTS: En face analyses revealed a significant correlation between radiolabeled G11 and fat-stained areas, increasing from 4 to 24 h, with a correlation coefficient of 0.92 (P < 0.0001) and an average signal-to-noise ratio of 104:1 at 24 h. Plaque imaging using L19 showed similar results (r = 0.86; P < 0.0001; signal-to-noise ratio, 72:1 at 24 h). Uptake of radiolabeled antibodies in histologic sections colocalized with fat staining and activated macrophages in aortic plaques. Biodistribution analyses confirmed specific accumulation in aortic plaques as well as rapid blood pool clearance of the antibodies 24 h after injection. Immunofluorescence analyses revealed increased expression of tenascin and fibronectin isoforms in macrophage-rich plaques. CONCLUSION: The antibody G11, specific to the C domain of tenascin-C, visualizes murine atherosclerotic plaques ex vivo. In conjunction with the increased expression of the C domain of tenascin-C in macrophage-rich plaques, the colocalization of G11 uptake with activated macrophages, and the favorable target-to-blood ratio at 24 h, this antibody may be useful for molecular imaging of advanced atherosclerotic plaques in the intact organism. 相似文献
14.
Antonio Bobbio Alfredo Chetta Paolo Carbognani Eveline Internullo Alessia Verduri Giulianoezio Sansebastiano Michele Rusca Dario Olivieri 《European journal of cardio-thoracic surgery》2005,28(5):754-758
OBJECTIVE: Pulmonary Function Tests (PFT) and Cardio-Pulmonary Exercise Testing (C-PET) are useful to evaluate operability in functionally compromised patients. Although modifications of PFT and C-PET after lung surgery have been widely explored, little information exists as to modifications of exercise capacity in COPD patients undergoing lung resection. We prospectively analyzed the changes in PFT and C-PET in patients with COPD after a pulmonary lobar resection. METHODS: From January 2003 to March 2004 all patients scheduled for lung resection were considered for participation in the study protocol. Those patients with a preoperative diagnosis of COPD on PFT were explored through a C-PET. Only patients who had undergone a lobar pulmonary resection were subsequently considered; these patients had a new complete cardio-respiratory evaluation 3 months after surgery. The pre- and postoperative values compared were those of FEV1, TLC, DLCO, VO2max, and VE/VCO2. Data are expressed as mean +/- standard deviation (SD). Statistic evaluation was made using the Wilcoxon test. RESULTS: During this period 11 patients completed the study protocol. Ten patients underwent surgery for NSCLC and one for a pulmonary aspergilloma. Nine lobectomies and two bilobectomies were performed. In the study population, the preoperative mean value of FEV1 resulted as being 53% (SD+/-20) of the predicted mean value, that of TLC 120% (SD+/-35) and that of DLCO 65% (SD+/-27). The preoperative mean value of VO2max resulted as being 17.8 ml/Kg/min (SD+/-3.25) and mean VE/VCO2 resulted as being 35.7 (SD+/-4). Three months after surgery the measured mean value of FEV1 was 53% (SD+/-18), that of TLC was 99% (SD+/-24) and that of DLCO 52% (SD+/-18). The mean value of VO2max resulted as being 14.1 ml/Kg/min (SD+/-3.04) and that of VE/VCO2 was 42.5 (SD+/-12.8). Statistical analysis of PFT values showed that FEV1 and DLCO were not significantly modified (P > 0.05); in contrast, TLC had significantly decreased (P = 0.008). VO2max had significantly decreased (P = 0.004) and VE/VCO2 had significantly increased (P = 0.018). CONCLUSIONS: Three months after a lobar pulmonary resection, patients with COPD were found to have a significant decrease in exercise tolerance. PFT alone can underestimate the postoperative loss of exercise capacity through exercise. 相似文献
15.
Dario Giugliano Antonio Ceriello Katherine Esposito 《Journal of the American College of Cardiology》2006,48(4):677-685
Reducing the incidence of coronary heart disease with diet is possible. The main dietary strategies include adequate omega-3 fatty acids intake, reduction of saturated and trans-fats, and consumption of a diet high in fruits, vegetables, nuts, and whole grains and low in refined grains. Each of these strategies may be associated with lower generation of inflammation. This review examines the epidemiologic and clinical evidence concerning diet and inflammation. Dietary patterns high in refined starches, sugar, and saturated and trans-fatty acids, poor in natural antioxidants and fiber from fruits, vegetables, and whole grains, and poor in omega-3 fatty acids may cause an activation of the innate immune system, most likely by an excessive production of proinflammatory cytokines associated with a reduced production of anti-inflammatory cytokines. The whole diet approach seems particularly promising to reduce the inflammation associated with the metabolic syndrome. The choice of healthy sources of carbohydrate, fat, and protein, associated with regular physical activity and avoidance of smoking, is critical to fighting the war against chronic disease. Western dietary patterns warm up inflammation, while prudent dietary patterns cool it down. 相似文献
16.
Adoniram M Figueiredo Renato S Poggetti Fabio G Quintavalle Belchor Fontes Moise Dalva Riad N Younes Fabio B Jatene Dario Birolini 《World journal of emergency surgery : WJES》2007,2(1):5
Background
Heart chambers rupture in blunt trauma is uncommon and is associated with a high mortality. The determinant factors, and the incidence of isolated heart chambers rupture remains undetermined. Isolated rupture of the right atrium appendage (RAA) is very rare, with 8 cases reported in the reviewed literature. The thin wall of the RAA has been presumed to render this chamber more prone to rupture in blunt trauma. 相似文献17.
Ilham Bettahi David Pozo Carmen Osuna Russel J. Reiter Dario Acuña-Castroviejo Juan M. Guerrero 《Journal of pineal research》1996,20(4):205-210
Abstract: In this report, rat hypothalamic nitric oxide synthase (NOS) activity is shown to be partially inhibited by physiological concentrations of the pineal hormone melatonin. In vitro studies demonstrate that 1 nM melatonin, which approximates the physiological concentration of the hormone at night, significantly inhibited NOS activity. In vivo studies show that administering melatonin or collecting the hypothalamus from animals at night, when endogenous melatonin levels are elevated, results in a significant decrease of NOS activity. Results also show that calmodulin may be involved in this process since its presence in the incubation medium prevents the inhibitory effect of melatonin on NOS activity. 相似文献
18.
19.
Verapamil inhibits interleukin-6 and vascular endothelial growth factor production in primary cultures of keloid fibroblasts. 总被引:10,自引:0,他引:10
G Giugliano D Pasquali A Notaro S Brongo G Nicoletti F D'Andrea A Bellastella A A Sinisi 《British journal of plastic surgery》2003,56(8):804-809
An increased secretion of cytokines and growth factors has been hypothesised to play a role in the abnormal growth of keloid fibroblasts. The aim of this study was to evaluate the effect of the calcium antagonist verapamil on the interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) secretion, as well as on cellular growth, in primary cultures of fibroblasts derived from the central part of keloid lesions. These cells grew faster than peripheral keloid and nonkeloid fibroblasts, and, in long-term cultures, became stratified assuming a three-dimensional structure. Compared with peripheral and nonkeloid fibroblasts, central keloid fibroblasts presented an increased production of both IL-6 and VEGF (P<0.03 and P<0.005, respectively). Verapamil (100 microM) decreased IL-6 and VEGF production (P<0.03 and P<0.005, respectively) in central keloid fibroblasts cultures at 72 h. Moreover, verapamil decreased cellular proliferation by 29% and increased apoptosis to an absolute value of 8%. The results of this study demonstrate that in primary cultures of central keloid fibroblasts verapamil reduces the sustained basal IL-6 and VEGF production and inhibits cell growth; these data may offer the link with the beneficial effect of calcium antagonists on keloid scars in vivo. 相似文献
20.
Giuseppe Galardi Silvestro Micera Jacopo Carpaneto Silvana Scolari Massimo Gambini Paolo Dario 《Movement disorders》2003,18(11):1358-1367
We developed an automated and objective method to measure posture and voluntary movements in patients with cervical dystonia using Fastrack, an electromagnetic system consisting of a stationary transmitter station and four sensors. The junction lines between the sensors attached to the head produced geometrical figures on which the corresponding aspects of the head were superimposed. The head position in the space was reconstructed and observed from axial, sagittal, and coronal planes. Four patients with cervical dystonia and 6 healthy subjects were studied. Each patient was representative of one of the typical patterns of cervical dystonia. The study allowed the authors to collect quantitative data on posture and range of motion of the head. This pilot study demonstrates the efficacy of the Fastrack system to objectively measure the head position in cervical dystonia patients. 相似文献