全文获取类型
收费全文 | 6030篇 |
免费 | 352篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 72篇 |
儿科学 | 163篇 |
妇产科学 | 154篇 |
基础医学 | 639篇 |
口腔科学 | 203篇 |
临床医学 | 433篇 |
内科学 | 1699篇 |
皮肤病学 | 48篇 |
神经病学 | 677篇 |
特种医学 | 236篇 |
外国民族医学 | 2篇 |
外科学 | 839篇 |
综合类 | 10篇 |
预防医学 | 208篇 |
眼科学 | 39篇 |
药学 | 326篇 |
中国医学 | 9篇 |
肿瘤学 | 654篇 |
出版年
2023年 | 56篇 |
2022年 | 95篇 |
2021年 | 143篇 |
2020年 | 109篇 |
2019年 | 142篇 |
2018年 | 141篇 |
2017年 | 103篇 |
2016年 | 138篇 |
2015年 | 161篇 |
2014年 | 185篇 |
2013年 | 281篇 |
2012年 | 445篇 |
2011年 | 372篇 |
2010年 | 250篇 |
2009年 | 214篇 |
2008年 | 365篇 |
2007年 | 359篇 |
2006年 | 343篇 |
2005年 | 361篇 |
2004年 | 341篇 |
2003年 | 296篇 |
2002年 | 253篇 |
2001年 | 119篇 |
2000年 | 120篇 |
1999年 | 115篇 |
1998年 | 52篇 |
1997年 | 54篇 |
1996年 | 53篇 |
1995年 | 39篇 |
1994年 | 48篇 |
1993年 | 37篇 |
1992年 | 65篇 |
1991年 | 48篇 |
1990年 | 53篇 |
1989年 | 64篇 |
1988年 | 50篇 |
1987年 | 35篇 |
1986年 | 34篇 |
1985年 | 37篇 |
1984年 | 24篇 |
1983年 | 29篇 |
1982年 | 20篇 |
1981年 | 13篇 |
1980年 | 13篇 |
1979年 | 20篇 |
1978年 | 12篇 |
1977年 | 16篇 |
1975年 | 8篇 |
1974年 | 10篇 |
1972年 | 14篇 |
排序方式: 共有6411条查询结果,搜索用时 15 毫秒
11.
Eugenio Neri Lucio Barabesi Dimitrios Buklas Luca A. Vricella Antonio Benvenuti Enrico Tucci Carlo Sassi Massimo Massetti 《European journal of cardio-thoracic surgery》2005,28(6):857-863
Objective: Increased dimension of the aortic root and proximal aorta is considered a significant risk factor for catastrophic events that involve the ascending aorta. The objective of this study was to determine the possible correlation between pre-dissection aortic diameter and the occurrence of Stanford type A aortic dissection. Methods: Samples of dissected ascending aortas were obtained from 220 patients at the time of their operation. Two groups were identified: patients with connective tissue disorders (Group 1, n = 94) and those without (Group 2, n = 126). Measurements of the true (intimal) lumen were conducted and extrapolated as reliable approximation of pre-dissection aortic diameter. The possible association of intimal diameter with anthropometric and demographic data was analyzed. Results: Median aortic diameter was, respectively, 41.8 and 41.3 mm for patients with and without connective tissue disorders (41.4 mm for the entire cohort). Data analysis indicated that 57% of patients had aortic diameter above 40 mm, while patients with frank aneurysm accounted only for 10%; this proportion was higher in Group 1 compared to Group 2 (17.2% vs 4.7%). Poor or no correlation was demonstrated between aortic size and any of the anthropometric or demographic variables essayed. Significant subgroup differences were found among patients with a history of cigarette smoking, hypertension, diabetes, chronic renal insufficiency, and bicuspid aortic valve. Conclusion: Although aortic diameter remains a strong indication for preventive surgery in patients with inherited connective tissue disorders, acute aortic dissection occurs rarely in the setting of true ascending aortic aneurysms, and despite normal or near-normal aortic size in more than one-third of subjects. Dissection superimposing on small aortic diameters can be regarded as an expression of substantial functional tissue susceptibility to aortic catastrophic events. 相似文献
12.
Marco Cirillo Andrea Amaducci Emmanuel Villa Margherita Dalla Tomba Federico Brunelli Zen Mhagna Giovanni Troise Eugenio Quaini 《Journal of cardiothoracic surgery》2006,1(1):40-11
Background
Long-term morphofunctional outcome may vary widely in surgical anterior left ventricular wall restoration, suggesting variability in post-surgical remodeling similar to that observed following acute myocardial infarction. The aim of this pilot study was to demonstrate that surgical restoration obtained with a particular shape of endoventricular patch leads to steady morphofunctional ventricular improvement when geometry, volume and residual akinesia can be restored as normal as possible. 相似文献13.
Luca Belli M.D. Alberto Reggiori M.D. Eugenio Cocozza M.D. Luciano Riboldi M.D. 《Skeletal radiology》1992,21(2):107-109
Tropical pyomyositis is an infection of muscles mainly presenting in black people, occurring in the trunk and limbs. At Hoima Hospital, Uganda, 58 patients (30 men and 28 women) with a mean age of 21 years have been investigated by ultrasound; a total of 81 lesions were present. Two different characteristic images were found; abscess was present in 65 cases while 16 patients showed a diffuse infiltration among the muscular fibers. These two different images correspond to the two stages of histologic and clinical progression described by other authors. Ultrasound is useful to demonstrate the progression of pyomyositis and to determine when and where to drain any abscess. 相似文献
14.
BACKGROUND. The relation between body mass index and acute myocardial infarction was analyzed using data from a multicentric case-control study conducted in Italy between September 1988 and June 1989 within the framework of the GISSI-2 trial. METHODS. Subjects were 916 patients with acute myocardial infarction and no history of cardiovascular disease and 1,106 controls hospitalized for acute conditions not related to known or suspected risk factors for ischaemic heart disease. RESULTS. Relative to the lowest quintile of the Quetelet Index (weight/height2) the estimated risks for subsequent quintiles were 1.2 (95% confidence intervals, (CI): 0.9 to 1.6), 1.7 (95% CI: 1.2 to 2.2), 1.8 (95% CI: 1.4 to 2.4), and 2.2 (95% CI: 1.7 to 3.0) when adjustment was made for age, sex, education, and smoking habits by means of logistic regression. The association was consistent across strata of sex, education, and smoking status, but not age. The estimated risk for subjects in the fifth quintile of the Quetelet Index relative to those in the first was 4.1 under 55 years of age, but only 1.7 between 55 and 64 years and 1.5 above age 65. CONCLUSION. The relation between body mass and myocardial infarction was explained, at least in part, by higher serum cholesterol levels and the prevalence of diabetes and hypertension among fatter subjects. This does not, however, totally eclipse a possible causal relation between body mass and risk of myocardial infarction, since these conditions are a consequence, rather than a confounder, of overweight. 相似文献
15.
Liviana Da Dalt Silvia Callegaro Silvia Carraro Barbara Andreola Massimo Corradi Eugenio Baraldi 《Pediatric allergy and immunology》2007,18(2):100-104
Respiratory syncytial virus (RSV) bronchiolitis is a very common infection in infants and, after the acute phase, a number of patients develop a reactive airway disease that lasts for years. Although the pathogenesis of the lung damage after RSV bronchiolitis is still largely unknown, previous studies suggest that leukotrienes may play an active part in it. The aim of this study was to measure leukotriene levels in the nasal lavage fluid (NLF) collected in infants during RSV bronchiolitis and 1 month later. Cysteinyl leukotrienes (Cys-LTs) and leukotriene B(4) (LTB(4)) were measured in the NLF of 22 infants with their first episode of RSV bronchiolitis and 16 healthy infants. A second NLF sample was collected to measure leukotriene levels 1 month after the acute disease. NLF Cys-LT levels were significantly higher in infants with RSV bronchiolitis than in healthy controls [950 pg/ml (285.5-2155.9) vs. 110.5 pg/ml (66.5-451.3), p = 0.01], and they remained so a month after the acute infection (p = 0.02). A subanalysis showed no difference in Cys-LTs concentrations, either between bronchiolitis infants with and without a family history of atopy, or between those with and without passive exposure to cigarette smoke. No significant difference was found between the LTB(4) levels measured in the bronchiolitis cases and the control children. Cys-LTs are significantly increased in the NLF of infants with acute RSV bronchiolitis, and remain so at 1-month follow-up, suggesting a possible role of these eicosanoids in the pathogenesis of the disease. 相似文献
16.
Gianmauro Sacchetti Eugenio Inglese Angelo S Bongo Franco Aina Marco Brambilla Alberto Baroli Carmelo Cernigliaro Pierfranco Dellavesa Edgardo Pittaluga Marco Rudoni 《European journal of nuclear medicine and molecular imaging》1997,24(10):1230-1236
The aim of this study was to determine the diagnostic accuracy of technetium-99m tetrofosmin myocardial imaging for the localization
of coronary artery stenoses of different degrees of severity. Stress-rest single-photon emission tomography (SPET) was performed
on separate days in 80 patients (64 males, 16 females; mean age 61 years; 43 patients with previous myocardial infarction;
18 patients with pharmacological stress), within 6 months of coronary angiography. Scintigraphic images were blindly and independently
evaluated by three observers. Coronary stenosis was defined as a >50% narrowing in luminal diameter; severe stenosis was defined
as a proximal stenosis of >75% or a peripheral stenosis of >90%. Coronary angiography revealed normal coronary arteries or
insignificant coronary stenosis in 13 patients and significant coronary stenoses in 67 patients. The sensitivity and specificity
of 99mTc-tetrofosmin SPET in respect of severely stenosed vessels were, respectively, 80% and 65% for the left anterior descending
artery (LAD), 100% and 46% for the right coronary artery (RCA) and 58 and 78% for the left circumflex artery (LCx) territories.
Considering all the significantly stenosed vessels, a significant decrease in sensitivity was observed for LAD territories
(to 59%, P=0.05), and a nonsignificant decrease for RCA (88%) and LCx (47%) territories while specificity values remained essentially
unchanged. No significant changes in sensitivity or specificity were observed when regions with previous myocardial infarction
were excluded. In conclusion, the sensitivity of 99mTc-tetrofosmin SPET for the localization of individual stenosed vessels is only moderate when all significant stenoses are
considered, but the ability of this technique to predict the location of severe coronary artery stenoses seems satisfactory,
with the exception of the low specificity in respect of RCA territories.
Received 26 April and in revised form 7 June 1997 相似文献
17.
Andrea Gallamini Alberto Biggi Adriana Fruttero Francesco Pugno Giobatta Cavallero Patrizia Pregno Mariella Grasso Chiara Farinelli Alessandro Leone Eugenio Gallo 《European journal of nuclear medicine and molecular imaging》1997,24(12):1499-1506
The purpose of this study was threefold: to evaluate the role of gallium-67 scintigraphy in the staging of low-grade non-Hodgkin’s
lymphomas (LGNHL), to assess the relationship between the expression of CD71 on the surface of the neoplastic cells and the
67Ga uptake by the tumour, and to establish the contribution of 67Ga scan in defining the prognosis of LGNHL. Forty-eight patients with untreated LGNHL diagnosed in a single institution over
a decade were reviewed. The end point of the study was survival of the patients according to the scintigraphic 67Ga score at diagnosis. In addition to 67Ga scan, other prognostic variables were studied, relating to the neoplastic burden, the biology of the tumour and the host.
Univariate and multivariate analyses were used. 67Ga scan identified only 116/286 (41%) nodes involved by lymphoma that were detected by clinical examination or computed tomography
scan. A scintigraphic scoring system with an arbitrary cut-off value of 3 (high scan score) was able to predict patients with
a dismal prognosis: with a mean follow-up of 47 months (range: 1–146 months) the median survival time was 28 months in patients
with a high scan score and 74 months in patients with a low scan score (P=0.002). CD71 values were 27.4%±14.9% (mean ±SD) in the former and 8.9%±7.2% in the latter (P=0.0001). Only performance status and extranodal sites were significant variables for prognosis in multivariate analysis.
It is concluded that 67Ga scan is inaccurate in staging but might be very important in defining the prognosis in LGNHL, in association with other
prognostic variables.
Received 1 May and in revised form 6 August 1997 相似文献
18.
L Santoro A Perretti A Filla G De Michele B Lanzillo F Barbieri C Crisci P G Rippa G Caruso 《Journal of the neurological sciences》1992,113(1):43-49
An electrophysiologic and histologic study was performed on 18 patients affected by early onset cerebellar ataxia with retained tendon reflexes (EOCA). Sensory and motor conduction velocity (SCV, MCV) was measured along peripheral nerves in all patients, somatosensory (SSEP) and brainstem auditory evoked potentials (BAEP) were recorded in 13; cortical stimulation (CS) in 12, and sural nerve biopsy in 4 patients were also performed. The results as a whole allow a division of EOCA patients into 2 groups: with (7 patients) and without (11 patients) peripheral neuropathy. Among EOCA patients with neuropathy a differential diagnosis with Friedreich's disease patients was not possible according to BAEPs and CS, while SSEPs could differentiate 2 out 5 patients in whom they were performed. 相似文献
19.
Distal radius fractures are common in children, yet complications are rare. A rarely described complication, acute volar compartmental syndrome, occurred in a 15-year-old boy. An accurate physical examination and awareness of the syndrome are essential for diagnosis. Compartmental pressures can be obtained easily and afford a rapid means of corroboration. Once the diagnosis is established, adequate decompression of all involved compartments, including carpal tunnel release, is essential. The literature is unclear regarding the etiology of this complication. There is nothing structurally intrinsic to the distal radius that should lead to a compartmental syndrome. Both the amount of soft tissue damage at the time of fracture and the mode of immobilization (excessive elevation, constricting splint, etc.) are the ultimate determinants of a successful (or unsuccessful) outcome. 相似文献
20.
Lauro Cortigiani Riccardo Bigi Rosa Sicari Patrizia Landi Francesco Bovenzi Eugenio Picano 《Journal of the American College of Cardiology》2006,47(3):605-610
OBJECTIVES: We sought to compare the prognostic value of pharmacological stress echocardiography (SE) in diabetic and nondiabetic patients with known or suspected coronary artery disease. BACKGROUND: Although SE is a useful tool for risk stratification of patients with diabetes, it has not been established whether it retains the same prognostic information in diabetic patients compared with nondiabetic patients. METHODS: A total of 5,456 patients (749 diabetics) undergoing dipyridamole (n = 3,306) or dobutamine (n = 2,150) SE were prospectively followed up for the occurrence of hard events (death and/or nonfatal myocardial infarction). RESULTS: During a median time of 31 months, 411 deaths and 236 infarctions occurred. There were 132 events in diabetic patients and 515 in nondiabetic patients (18% vs. 11%, respectively; p < 0.0001). Moreover, 1,607 (29%) patients underwent coronary revascularization and were censored. Ischemia at SE, resting wall motion score index, and age were independent predictors of death and hard events in both diabetic and nondiabetic patients. Compared with a normal test, ischemia and scar test patterns were associated to significantly lower age-corrected five-year hard event-free survival in diabetic as well as nondiabetic patients. However, a normal test was associated with a greater than two-fold annual event rate in diabetic patients as compared with nondiabetics who were either younger (2.6% vs. 1.0%) or older (5.5% vs. 2.2%) than 65 years of age. CONCLUSIONS: Stress echocardiography is equally effective in risk stratifying diabetic and nondiabetic patients independently of age. However, the normal test result predicts a less favorable outcome in diabetic than in nondiabetic patients. 相似文献