全文获取类型
收费全文 | 1232篇 |
免费 | 61篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 51篇 |
妇产科学 | 24篇 |
基础医学 | 164篇 |
口腔科学 | 100篇 |
临床医学 | 94篇 |
内科学 | 236篇 |
皮肤病学 | 65篇 |
神经病学 | 60篇 |
特种医学 | 57篇 |
外科学 | 95篇 |
综合类 | 37篇 |
预防医学 | 143篇 |
眼科学 | 26篇 |
药学 | 96篇 |
中国医学 | 4篇 |
肿瘤学 | 43篇 |
出版年
2023年 | 7篇 |
2022年 | 22篇 |
2021年 | 29篇 |
2020年 | 24篇 |
2019年 | 32篇 |
2018年 | 35篇 |
2017年 | 22篇 |
2016年 | 40篇 |
2015年 | 52篇 |
2014年 | 52篇 |
2013年 | 65篇 |
2012年 | 92篇 |
2011年 | 111篇 |
2010年 | 66篇 |
2009年 | 46篇 |
2008年 | 68篇 |
2007年 | 64篇 |
2006年 | 56篇 |
2005年 | 47篇 |
2004年 | 28篇 |
2003年 | 23篇 |
2002年 | 21篇 |
2001年 | 21篇 |
2000年 | 13篇 |
1999年 | 25篇 |
1998年 | 40篇 |
1997年 | 29篇 |
1996年 | 16篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 14篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 10篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 11篇 |
1984年 | 3篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1980年 | 7篇 |
1977年 | 3篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1970年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有1313条查询结果,搜索用时 15 毫秒
81.
Scintiscans of liver and spleen using technetium 99m sulphur colloid in 15 infants with extrahepatic biliary atresia and 11 infants with severe obstructive jaundice (7 with genetic deficiency of alpha 1-antitrypsin) showed similar hepatic size, pattern of isotope uptake, and splenic abnormality with no distinguishing features. In 37 older children with a variety of liver disorders, the scan was invaluable in showing filling defects in five instances. Selenomethionine was taken up not only by the two filling defects due to hepatoblastoma but also in a haemangioendothelioma. In the remaining patiens liver scanning confirmed hepatic abnormality and the necessity for more specific invasive diagnostic investigations. 相似文献
82.
Lucieni Oliveira Conterno Silvana Martins Dias Toni Rubiana Gon?alves Konkiewitz Elaine Salla Guedes Rubens Tofano de Barros Marcos Gradim Tiveron 《Brazilian Journal Of Cardiovascular Surgery》2014,29(2):167-176
Objective
this study aimed to determine the incidence of nosocomial infections, the risk factors and the impact of these infections on mortality among patients undergoing to cardiac surgery.Methods
Retrospective cohort study of 2060 consecutive patients from 2006 to 2012 at the Santa Casa de Misericórdia de Marília.Results
351 nosocomial infections were diagnosed (17%), 227 non-surgical infections and 124 surgical wound infections. Major infections were mediastinitis (2.0%), urinary tract infection (2.8%), pneumonia (2.3%), and bloodstream infection (1.7%). The in-hospital mortality was 6.4%. Independent variables associated with non-surgical infections were age > 60 years (OR 1.59, 95% CI 1.09 to 2.31), ICU stay > 2 days (OR 5, 49, 95% CI 2.98 to 10, 09), mechanical ventilation > 2 days (OR11, 93, 95% CI 6.1 to 23.08), use of urinary catheter > 3 days (OR 4.85 95% CI 2.95 -7.99). Non-surgical nosocomial infections were more frequent in patients with surgical wound infection (32.3% versus 7.2%, OR 6.1, 95% CI 4.03 to 9.24). Independent variables associated with mortality were age greater than 60 years (OR 2.0; 95% CI 1.4 to3.0), use of vasoactive drugs (OR 3.4, 95% CI 1.9 to 6, 0), insulin use (OR 1.8; 95% CI 1.2 to 2.8), surgical reintervention (OR 4.4; 95% CI 2.1 to 9.0) pneumonia (OR 4.3; 95% CI 2.1 to 8.9) and bloodstream infection (OR = 4.7, 95% CI 2.0 to 11.2).Conclusion
Non-surgical hospital infections are common in patients undergoing cardiac surgery; they increase the chance of surgical wound infection and mortality. 相似文献83.
The effects of prenatal exposure to dichlorvos (DDVP), an organophosphate (OP) pesticide, on pups' physical and neurobehavioral developments were investigated. Forty pregnant rats were treated by gavage with 8.0 mg/kg DDVP or its vehicle (1 ml/kg) from the 6th to the 15th day of pregnancy. At birth, pups were weighed, the litters culled to eight animals (four male and four female), and then observed for physical (pinna detachment, incisor eruption, eye opening, testes descent, and vaginal opening) and neurobehavioral developments (palmar grasp, surface righting, negative geotaxis, and open-field behaviors). As adults, open-field, apomorphine-induced stereotypy, and passive avoidance behaviors were also assessed. Results showed no differences between the body weight of DDVP and control-treated groups. No differences were observed on the measures of physical and neurobehavioral development. Locomotor activity of male pups at 21 days of age was decreased by DDVP exposure. Adult experimental offspring showed a decreased locomotor frequency and an increased immobility duration on open-field behavior in relation to control animals; the apomorphine-induced stereotyped behavior was decreased by the pesticide exposure as well as performance on the passive avoidance task. These data suggest that prenatal DDVP exposure was able to decrease offspring motor function (adolescence and adults) and conditioned response learning, probably by interference with the cholinergic-dopaminergic balance of activity involved with the control of motor function as well as the cholinergic system that modulates learning process. 相似文献
84.
Bile duct obstruction: radiologic evaluation of level, cause, and tumor resectability 总被引:6,自引:0,他引:6
Gibson RN; Yeung E; Thompson JN; Carr DH; Hemingway AP; Bradpiece HA; Benjamin IS; Blumgart LH; Allison DJ 《Radiology》1986,160(1):43-47
In a prospective study of 65 patients with bile duct obstruction, various radiologic modalities were compared for their capability to demonstrate the level and cause of obstruction and to indicate accurately tumor resectability. Ultrasound (US) was performed in 65 patients, computed tomography (CT) in 51, direct cholangiography (DC) in 57, and angiography in 35. The level of obstruction was correctly indicated by US in 95% of patients and by CT in 90%, and the cause was correctly indicated by US in 88%, by CT in 63%, and by DC in 89%. In predicting tumor resectability, US was correct in 71% of patients, compared with 42% for CT, 58% for DC, and 25% for angiography. US therefore appears to be the single most useful modality in the evaluation bile duct obstruction. 相似文献
85.
PURPOSE: To determine whether orientation discrimination deficits in migraine, which have been found to depend on the spatial frequency of the stimulus, are due to precortical dysfunction or to abnormal patterns of orientation tuning at cortical loci. Further, to assess whether any cortical involvement is restricted to the striate cortex or whether higher cortical areas are also involved. Orientation-specific abnormalities would provide evidence of cortical dysfunction. METHODS: Orientation-discrimination and contrast-detection thresholds were assessed at cardinal (0 degrees) and oblique (45 degrees) orientations using explicit lines defined by Gabor patches. To test for extrastriate dysfunction, participants made orientation judgments using virtual lines defined by two widely spaced circles. Migraine history, migraine triggers, and pattern sensitivity were also assessed. Twenty migraineurs (10 with visual aura, 10 without) and 20 control participants were tested. RESULTS: Orientation-discrimination thresholds were lower for discriminations made about the cardinal axis than for discriminations made about the oblique axis, a well-documented phenomenon known as the oblique effect. Relative to the control group, the migraine group exhibited orientation-specific sensitivity losses on explicit and virtual judgments. Orientation-discrimination thresholds about the oblique axis were significantly elevated in the migraine group. In contrast, the migraine and control groups' detection thresholds did not differ. CONCLUSIONS: These findings reflect abnormal function of striate and extrastriate cortex in migraine. In addition, the discrimination data are consistent with wider orientation-tuning curves for orientation-sensitive cells in migraine, whereas the detection data suggest peak sensitivity does not differ between the groups. 相似文献
86.
87.
88.
W R Couet B G Reigner J P Guedes T N Tozer 《Journal of pharmacokinetics and biopharmaceutics》1991,19(3):271-285
A pharmacokinetic model incorporating saturable rate of absorption of the Michaelis-Menten type was recently developed to fit cefatrizine (CFZ) plasma concentrations with time following oral administration of 500-mg capsules to humans. This model (MM) was statistically superior to models incorporating either first-order or zero-order absorption. However, the MM model does not predict the reduction in extent of absorption with dose observed in vivo. In this study, a model is proposed in which a time constraint, delta t, is added to the MM model. This new model (MM-delta t) is tested with data following doses of 250, 500, and 1000 mg of CFZ. When delta t is set to 1.5 hr, the predicted relative changes with dose in bioavailability, F, peak plasma concentration, Cmax, the time at which the peak concentration occurs tmax, and the mean absorption time, MAT, are generally in good agreement with the experimental data. The time interval of 1.5 hr is compatible with passage by a limited region within the small intestine where drug is absorbed by a facilitated transport mechanism. Influence of each absorption model parameter (Vmax, Km, and delta t) on total area under the concentration versus time curve (AUC), F, Cmax, and tmax, is assessed by simulation. The MM-delta t model is able to summarize the nonlinerity observed in both rate and extent of absorption. 相似文献
89.
90.
Alfonso Sánchez-Muñoz César Mediola Fernández Paloma Poza Guedes Gabriela Canto Díez Susana Bezares Montes Hernán Cortés Funes 《Clinical & translational oncology》2002,4(2):68-71
The increasing use of carboplatin and paclitaxel for the treatment of cancer, especially in ovarian and lung carcinomas has led to the observation of a growing number of hypersensitivity reactions to these drugs. Hypersensitivity to carboplatin usually appears in heavily pre-treated patients, and it is difficult to use carboplatin in posterior treatments. Hipersensitivity to paclitaxel, in contrast, usually takes place during the first or second infusions, although frequently it can be used again safely with a correct premedication or with the appropriate desensitization techniques. We review here the clinical, diagnostic and therapeutic management of hypersensitivity to carboplatin and paclitaxel. We provide the guidelines for the correct distinction between the two types of reactions and the clinical management. 相似文献