全文获取类型
收费全文 | 6754篇 |
免费 | 361篇 |
国内免费 | 50篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 107篇 |
妇产科学 | 99篇 |
基础医学 | 891篇 |
口腔科学 | 535篇 |
临床医学 | 480篇 |
内科学 | 1675篇 |
皮肤病学 | 105篇 |
神经病学 | 891篇 |
特种医学 | 176篇 |
外科学 | 928篇 |
综合类 | 28篇 |
一般理论 | 4篇 |
预防医学 | 316篇 |
眼科学 | 162篇 |
药学 | 375篇 |
中国医学 | 28篇 |
肿瘤学 | 289篇 |
出版年
2024年 | 3篇 |
2023年 | 71篇 |
2022年 | 145篇 |
2021年 | 293篇 |
2020年 | 183篇 |
2019年 | 237篇 |
2018年 | 272篇 |
2017年 | 151篇 |
2016年 | 191篇 |
2015年 | 248篇 |
2014年 | 310篇 |
2013年 | 348篇 |
2012年 | 547篇 |
2011年 | 622篇 |
2010年 | 310篇 |
2009年 | 270篇 |
2008年 | 479篇 |
2007年 | 432篇 |
2006年 | 407篇 |
2005年 | 360篇 |
2004年 | 324篇 |
2003年 | 281篇 |
2002年 | 248篇 |
2001年 | 48篇 |
2000年 | 37篇 |
1999年 | 35篇 |
1998年 | 46篇 |
1997年 | 25篇 |
1996年 | 32篇 |
1995年 | 22篇 |
1994年 | 18篇 |
1993年 | 19篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 14篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 11篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1972年 | 5篇 |
1966年 | 3篇 |
排序方式: 共有7165条查询结果,搜索用时 781 毫秒
61.
Emanuele Nicolai Alberto Cuocolo Leonardo Pace Antonio Nappi Pasquale Sullo Stefania Cardei Luigi Argenziano Fiorenzo Squame Peter J. Ell Marco Salvatore 《Journal of nuclear cardiology》1996,3(1):9-17
Background
Exercise and dipyridamole 99mTc-labeled methoxy isobutyl isonitrile (MIBI) myocardial scintigraphy have been widely used for the diagnosis of coronary artery disease (CAD). However, only limited data on adenosine 99mTc-labeled MIBI cardiac imaging are currently available. This study was designed to assess the accuracy of quantitative adenosinerest 99mTc-labeled MIBI tomography in the diagnosis and localization of CAD.Methods and Results
Fifty-seven consecutive patients with suspected CAD who underwent coronary angiography and 22 normal volunteers were studied. All patients underwent 99mTc-labeled MIBI tomography after administration of adenosine (140 μg/kg intravenously for 6 minutes) and at rest. A total of 171 vascular coronary territories were analyzed quantitatively. All patients with CAD (≥50% luminal stenosis) (n=55) had abnormal 99mTc-labeled MIBI tomograms. The normalcy rate was 86% by quantitative analysis. Overall sensitivity, specificity, and diagnostic accuracy for detection of individual stenosed vessels were 84%, 87%, and 85%, respectively. In patients with one-vessel CAD (n=24), sensitivity and diagnostic accuracy in the detection of individual stenosed vessels were significantly (p<0.05) higher compared with patients with multivessel CAD (n=31). Moreover, 75% of patients with one-vessel disease showed a scintigraphic pattern characterized by the presence of perfusion defects in only one coronary artery territory, and 74% of patients with multivessel disease showed a scintigraphic pattern characterized by the presence of perfusion defects in two or more coronary artery territories. Sensitivity, specificity, and diagnostic accuracy for detecting individual diseased vessels were similar in patients without previous myocardial infarction (n=18) compared with those with previous myocardial infarction (n=39). In myocardial territories related to noninfarcted areas (n=124), sensitivity and specificity in the detection of stenosed vessels were 75% and 88%. In infarcted areas (n=47), sensitivity and specificity in the detection of stenosed vessels were 98% and 80% (differences not significant vs noninfarcted areas).Conclusions
Adenosine-controlled coronary vasodilation combined with quantitative 99mTc-labeled MIBI tomography is accurate for identifying patients with CAD and localizing individual stenosed coronary arteries. 相似文献62.
Pasquale Sullo Alberto Cuocolo Emanuele Nicolai Stefania Cardei Antonio Nappi Fiorenzo Squame Eugenio M. Covelli Leonardo Pace Marco Salvatore 《European journal of nuclear medicine and molecular imaging》1996,23(6):648-655
The aim of this study was to evaluate the accuracy of quantitative 1-day exercise-rest technetium-99m tetrofosmin tomography in the identification of patients with coronary artery disease (CAD) and in the detection of individual stenosed coronary vessels. Sixty-one patients with suspected CAD who underwent coronary angiography and 13 normal volunteers were studied. All patients were submitted to two i.v. injections of99mTc-tetrofosmin, one at peak exercise (370 MBq) and the other (1110 MBq) at rest 3 h after exercise (images 15–30 min after injection for both studies). All patients with CAD (0% luminal stenosis) (n=50) had an abnormal99mTc-tetrofosmin tomogram. Only one patient without significant coronary narrowing showed abnormal findings. Overall sensitivity, specificity and diagnostic accuracy in the detection of individual stenosed vessels were 77%, 93% and 85%, respectively. Sensitivity and diagnostic accuracy in the identification of individuals stenosed coronary vessels were significantly higher (P<0.05) in patients with single-vessel disease (n=21) than in those with multivessel disease (n=29). Sensitivity, specificity and accuracy for detecting individual diseased vessels were similar in patients without previous myocardial infarction (n=26) and in those with previous myocardial infarction (n=35). In myocardial territories related to non-infarcted areas (n=128), sensitivity and specificity in the detection of stenosed vessels were 70% and 95%, respectively. In infarcted areas (n=55), sensitivity and specificity in the detection of stenosed vessels were 85% (P=NS vs non-infarcted areas) and 75% (P<0.05 vs non-infarcted areas), respectively. Finally, sensitivity was significantly lower (P<0.05) in vascular territories supplied by vessels with moderate stenosis (50%–75%) than in those supplied by vessels with severe stenosis (>75%). The results of this study demonstrate that quantitative 1-day exercise-rest99mTc-tetrofosmin single-photon emission tomographic imaging is a suitable and accurate technique to identify patients with CAD and to detect individual stenosed coronary vessels. 相似文献
63.
A group of six patients with a marked gastric lymphoid "hyperplasia", two of these with generalised lymphoma and the others suspected for primary gastric lymphoma, were investigated to discriminate between simple reactive hyperplasias and lymphomatous proliferations. Microscopical and ultrastructural examinations were not useful for this purpose but immunological data can give evidence of a two-fold nature of gastric lymphoid hyperplasia. Some cases are without immunological disorders, others are met with peripheral blood signs of immunological alterations similar to those observed in malignant lymphomas and in chronic lymphocytic leukemia. Only these latter cases should, in our opinion, be regarded as primitive gastric lymphomas. 相似文献
64.
65.
Mariana Borgognone Leonardo M Pérez Cecilia L Basiglio Justina E Ochoa Marcelo G Roma 《Toxicological sciences》2005,83(1):114-125
Hydrophobic bile salts induce either necrosis or apoptosis depending on the severity of the injury caused by them. Since bile salt-induced apoptosis is influenced by Ca2+- and protein kinase-signaling pathways, and both necrosis and apoptosis share common initiating mechanisms, we analyzed whether these signaling cascades also influence bile salt-induced necrosis in isolated rat hepatocytes. Taurochenodeoxycholate (TCDC, 0.25-1.50 mM, 2 h) reduced, in a dose-dependent manner, the percentage of viable hepatocytes, and increased the release of the cytosolic enzyme, lactate dehydrogenase (LDH) and alanine aminotransferase (ALAT), and that of the plasma membrane enzyme, alkaline phosphatase (AP). The PKC inhibitors, H7 (100 microM) and chelerythrine (2.5 microM), both prevented significantly TCDC-induced necrosis. On the contrary, the PKA activator, dibutyryl-cAMP, exacerbated TCDC-induced cell damage in a dose-dependent manner; this effect was more likely due to cAMP-mediated PKA activation, as the PKA inhibitor, KT5720 (1 microM), counteracted this effect. Instead, the intracellular Ca2+ chelator, BAPTA/AM (20 microM), was without effect. TCDC (1 mM) increased lipid peroxidation from 0.7 +/- 0.2 to 7.5 +/- 0.9 nmol of malondialdehyde per mg of protein, p < 0.001; the addition of the free radical scavenger, diphenyl-p-phenylendiamine, completely blocked this increase and prevented significantly TCDC-induced necrosis. PKC inhibition induced only a slight attenuation of TCDC-induced lipid peroxidation. Possible mechanisms accounting for the modulatory effect of signal transduction pathways on TCDC-induced necrosis, including signaling influence on TCDC transport events and TCDC-induced oxidative stress, are discussed. 相似文献
66.
Earl R. Burrell Heather A. Pines Edward Robbie Leonardo Coleman Ryan D. Murphy Kristen L. Hess Peter Anton Pamina M. Gorbach 《AIDS and behavior》2012,16(7):1816-1820
Mobile phone social networking applications such as GRINDR are potential tools for recruitment of men who have sex with men (MSM) for HIV prevention research. Demographics and sexual risk behaviors of men recruited through GRINDR and through traditional media were compared. GRINDR participants were younger (mean age 31 vs. 42, p?<?0.0001), more White identified (44 vs. 30?%, p?<?0.01), and had more sex partners in the previous 14 days (1.88 vs. 1.10, p?<?0.05) than other recruits. Email responses were less successful for enrollment than phone calls (5 vs. 50?%). This approach resulted in successful recruitment of younger and more educated, White identified MSM. 相似文献
67.
Leonardo Manzari Ann M. Burgess Ian S. Curthoys 《European archives of oto-rhino-laryngology》2012,269(2):685-691
Lermoyez syndrome (LS) has been regarded as a variant of Ménière’s disease (MD), but so far there have been very few cases
of LS reported in the literature, so such a conclusion is debatable. Specifying the pattern of auditory and vestibular changes
at attack using objective quantitative measures is important for understanding the mechanism responsible for MD and LS. Here
we report the first objective measures of dynamic otolith function and dynamic semicircular canal function in an LS patient
at the time of the attack as well as at quiescence, documenting the fluctuation in otolith and semicircular canal function
in the patient. The very rapid changes in dynamic vestibular function at the time of the LS attack appear to complement some
of the rapid changes in auditory and vestibular function at the attack in Ménière’s disease, supporting the contention that
LS is a variant of MD. 相似文献
68.
Karla Palma Portes André de Campos Duprat Carmen Lucia Penteado Lancellotti Leonardo Silva Flávia Coelho de Souza 《Revista brasileira de otorrinolaringologia (English ed.)》2012,78(1):51-56
Fibrin sealants or fibrin glue are products made from human plasma proteins, which mimic the final pathway of the coagulation cascade. Its application to stimulate the healing process has been a topic of debate in the literature. The use of fibrin sealants in phonosurgery has been empirical; there have been no studies that investigate the action of fibrin sealant in Reinke's space.AimTo evaluate the effect of fibrin glue in healing of the vocal folds of pigs after surgical manipulation.Materials and MethodsThis was a prospective and experimental study. Six animals had both vocal folds incised. Sealant was applied in one of them; the other served as a control. After three months, the animals were sacrificed and a collagen count was carried out.ResultsThe side on which glue was applied had an average of 27.8% against 20.4% of the side without glue.ConclusionThe collagen concentration in the samples where the fibrin sealant was applied was significantly higher compared to samples without glue. Thus, the presence of a fibrin sealant stimulates fibrogenesis in this tissue. 相似文献
69.
Echocardiographic features of post−transcatheter aortic valve implantation thrombosis and endocarditis 下载免费PDF全文
Marco Spartera MD Francesco Ancona MD Marta Barletta MD Isabella Rosa MD Stefano Stella MD Claudia Marini MD Leonardo Italia MD Matteo Montorfano MD Azeem Latib MD Ottavio Alfieri MD Alberto Margonato MD Antonio Colombo MD Eustachio Agricola MD 《Echocardiography (Mount Kisco, N.Y.)》2018,35(3):337-345
70.
Alessandro Squizzato Davide Luciani Andrea Rubboli Leonardo Di Gennaro Raffaele Landolfi Carlo De Luca Fernando Porro Marco Moia Sophie Testa Davide Imberti Guido Bertolini 《Internal and emergency medicine》2013,8(8):695-702
Most cardiopulmonary diseases share at least one symptom with pulmonary embolism (PE). The aim of this study was to identify the most common acute causes of dyspnea, chest pain, fainting or palpitations, which diagnostic procedures were performed and whether clinicians investigate them appropriately. An Italian multicenter collaboration gathered 17,497 Emergency Department (ED) records of patients admitted from January 2007 to June 2007 in six hospitals. A block random sampling procedure was applied to select 800 hospitalised patients. Results of the overall 17,497 patients were obtained by weighting sampled cases according to the probability of the randomisation block variables in the whole population. The case-mix of enrolled patients was assessed in terms of cardiopulmonary symptoms, and the prevalence of acute disorders. The actual performance of procedures was compared with a measure of their accuracy as expected in the most common clinical presentations. PE occurred in less than 4% of patients with cardiopulmonary symptoms. Acute heart failure, pneumonia and chronic obstructive pulmonary disease exacerbation were the most likely diagnoses in patients with dyspnea. Acute myocardial infarction was present in roughly 10% of patients with chest pain. Atrial fibrillation was the prevalent diagnosis in patients with palpitations. Echocardiography, computed tomographic pulmonary angiography, perfusion lung scan, D-dimer test and B-type natriuretic peptide were performed less than expected from their accuracy. Diagnostic strategies, starting from non-specific symptoms and coping with the eventuality of PE, are likely to benefit from an increased awareness of the examination’s accuracy in discriminating among several competing hypotheses, rather than in testing the single PE suspicion. 相似文献