全文获取类型
收费全文 | 7454篇 |
免费 | 447篇 |
国内免费 | 39篇 |
专业分类
耳鼻咽喉 | 133篇 |
儿科学 | 250篇 |
妇产科学 | 128篇 |
基础医学 | 970篇 |
口腔科学 | 186篇 |
临床医学 | 579篇 |
内科学 | 1974篇 |
皮肤病学 | 84篇 |
神经病学 | 869篇 |
特种医学 | 323篇 |
外科学 | 999篇 |
综合类 | 30篇 |
一般理论 | 8篇 |
预防医学 | 434篇 |
眼科学 | 150篇 |
药学 | 394篇 |
中国医学 | 14篇 |
肿瘤学 | 415篇 |
出版年
2024年 | 6篇 |
2023年 | 61篇 |
2022年 | 178篇 |
2021年 | 360篇 |
2020年 | 209篇 |
2019年 | 282篇 |
2018年 | 332篇 |
2017年 | 228篇 |
2016年 | 226篇 |
2015年 | 283篇 |
2014年 | 350篇 |
2013年 | 408篇 |
2012年 | 635篇 |
2011年 | 645篇 |
2010年 | 339篇 |
2009年 | 282篇 |
2008年 | 510篇 |
2007年 | 441篇 |
2006年 | 376篇 |
2005年 | 423篇 |
2004年 | 366篇 |
2003年 | 272篇 |
2002年 | 244篇 |
2001年 | 58篇 |
2000年 | 52篇 |
1999年 | 46篇 |
1998年 | 42篇 |
1997年 | 42篇 |
1996年 | 28篇 |
1995年 | 25篇 |
1994年 | 22篇 |
1993年 | 16篇 |
1992年 | 18篇 |
1991年 | 18篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 12篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 4篇 |
1977年 | 3篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有7940条查询结果,搜索用时 343 毫秒
61.
Knorst Jessica Klöckner Brondani Bruna Tomazoni Fernanda Vargas Andressa Weber Cósta Marina Dutra da Silva Godois Leonardo Mendes Fausto Medeiros Ardenghi Diego Machado Ardenghi Thiago Machado 《Quality of life research》2021,30(6):1685-1691
Quality of Life Research - As people around the world are facing the Covid-19 outbreak, their perception of oral health problems could be changed. This study aimed to evaluate the immediate effects... 相似文献
62.
Renato Talamini Anna E. Barón Salvatore Barra Ettore Bidoli Carlo La Vecchia Eva Negri Diego Serraino Silvia Franceschi 《Cancer causes & control : CCC》1990,1(2):125-132
A hospital-based case-control study of renal cell cancer was conducted in northern Italy betwen 1986 and 1989, with 240 cases of renal cell cancer (150 males and 90 females), and 665 controls (445 males and 220 females) chosen on the basis of age, sex, and area of residence. No associations were found between renal cell cancer and: body mass index (BMI); number of cigarettes smoked; age at starting to smoke; years of smoking; consumption of wine, beer, spirits, coffee, decaffeinated coffee; tea; intake of animal protein, fruits, and vegetables; various resproductive factors; hormonal use; sexual habits; sexually transmitted diseases; or selected occupational exposures. The odds ratio (OR) was above unity in smokers (OR=1.34 for 15 cigarettes/day), but the trends in risk with dose or duration were not statistically significant. Significant positive associations were found between renal cell cancer and sources of fat intake, especially margarine (OR for highest vs lowest intake = 1.71), and oils (OR=1.89) whereas carrot intake showed a negative association (OR=0.62). Also, a history of nephrolithiasis and multiple episodes of cystitis showed weak positive associations (OR=2.00, 95 percent confidence interval (CI) 1.07–3.73; and OR=1.60, 95 percent CI 0.95–2.70, respectively).Address reprint requests to Dr Talamini. The work was conducted with the contribution of the Italian Association for Cancer Research, Milan, Italy and the CNR (Italian National Research Council) Applied Projects Oncology (Contract n. 85.02209.44).Drs Talamini, Barón, Barra, Bidoli, Serraino, and Franceschi are in the Epidemiology Unit, Aviano Cancer Center, Via Pedemontana Occ. 33081 Aviano (PN) Italy. At the time of this work, Dr Barón was a visiting biostatistician from the Department of Preventive Medicine and Biometrics, University of Colorado, Health Science Center, CO, funded by the National Cancer Institute (US) and the Italian National Research Council. Dr Franceschi is also chief of the Hormones and Sexual Factors and Cancer Working Group of the European Organization for Cooperation in Cancer Prevention Studies, Bruxelles, Belgium. Drs La Vecchia and Negri are in the Mario Negri Institute for Pharmacological Research, Milan, Italy. Dr La Vecchia is also in the Institute of Social and preventive Medicine, University of Lausanne, Switzerland. 相似文献
63.
The objectives of this study were: i) to analyse the effects of morphine and naloxone on the rat's behaviour in the hot plate test using an ethological approach, and ii) to compare the effectiveness of repeated versus single test paradigms. Animals received either morphine (0, 3, 6 or 9 mg/kg SC) or naloxone (0, 0.01, 0.1 or 1 mg/kg SC). For repeated hot plate measures, rats were tested before and 60, 120, 180 and 240 min following morphine treatment, as well as 30, 60, 90 and 120 min after naloxone injection. For the single test schedule, rats were tested only once 60 min after morphine or 30 min after naloxone administration, or at 60, 120, 180, 240 and 300 min after 9 mg/kg morphine treatment. Behaviour was videotaped and analysed by an ethogram and ethological techniques. A cluster analysis revealed that the most frequently displayed patterns could be categorised into exploratory sniffing reactions (walk-sniff, immobile-sniff) and noxious-evoked elements, including primary (paw-licking, stamping), escape (jumping, leaning posture) and independent (hindleg-withdrawal) patterns. During repeated tests, morphine treatment induced: i) a maximum hypoalgesic effect 60 min post-injection (noxious-evoked patterns were significantly reduced), and ii) an unexpected thermal hyperreactivity rebound effect after 120 min (paw-licking and hindleg-withdrawal were enhanced), although changes in hindpaw-licking are more indicative of a hyperalgesic rebound effect. Most changes were quite similar during the single test schedule at 60 and 120 min after morphine injection. With regard to naloxone treatment, jumping latency was significantly decreased during the repeated test schedule, but not on single exposure to the plate. Other elements were facilitated, however, in the single test (stamping, leaning posture, hindleg-withdrawal). The results indicated that both repeated and single tests paradigms are of value for testing the effects of morphine and naloxone on rats. However, under our conditions the single test paradigm gave a better picture of the overall effects of the drug. Learning as well as habituation and sensitization may mask certain effects during repeated tests. In conclusion, an ethological analysis of the rat's behaviour in the hot plate test following administration of morphine and naloxone has been validated in this study. 相似文献
64.
Diego Nuñez Jr. M.D. John D. Wester M.D. Kimberley A. Lentz M.D. Marco A. Amendola M.D. 《Emergency radiology》1996,3(1):20-24
This study was performed to evaluate whether consecutive arterial phase and portal venous phase scans of the upper abdomen are contributory in the evaluation of the liver in patients with blunt abdominal trauma. The purpose of the study was to determine whether such dual acquisition using helical computed tomography (HCT) provides improved definition of injuries and significant information about the dynamics of posttraumatic hemorrhage.During a 10-month period, all patients referred for evaluation of blunt abdominal trauma were scanned using a dual phase imaging technique. Two consecutive and comparable scan clusters were programmed to study the upper abdomen, with a slice collimation of 10 mm and a 11 pitch. Intravenous contrast medium was delivered at a rate of 2 ml/sec for a total of 125 ml, with scan delays of 30 and 70 seconds (arterial and venous phases of hepatic enhancement).Thirty-two patients with hepatic lacerations were encountered, and the images from both acquisitions were compared and graded according to lesion conspicuity. The presence of contrast medium extravasation associated with parenchymal injuries was also recorded.In 23 (72%) of the 32 patients, the liver injuries were better defined in the portal venous phase, and in eight (25%) patients, the lesions were equally shown in both phases. In only one case, the lesion was better demonstrated in the arterial phase. Contrast medium extravasation was noted in two patients at the site of liver laceration. In three additional cases, contrast medium extravasation was also noted in associated splenic injuries. In all of these patients, the extravasation (bleeding laceration) was seen only in the images corresponding to the portal venous phase.Dual phase HCT of the upper abdomen does not provide significant additional information in the evaluation of patients with liver injuries resulting from blunt abdominal trauma. With a single scan cluster through the upper abdomen after a 70-second injection-scan delay, lesion definition is optimal, and vascular opacification remains adequate. 相似文献
65.
Left atrial thrombi in non-rheumatic atrial fibrillation: assessment of prevalence by transesophageal echocardiography 总被引:1,自引:0,他引:1
To determine the prevalence of left atrial thrombus in hospitalized patients with non-rheumatic atrial fibrillation, 48 patients were consecutively studied with single-plane transesophageal echocardiography. There were 23 males (48%) and 25 females (52%). The mean age was 66±11 years (range 43–87). Thrombus was detected in 13 patients (27%) 11 were confined to the left atrial appendage, 1 to the atrial body and appendage, and 1 to the left upper pulmonary vein. Prevalence of atrial thrombus was not different among those patients with or without previous stroke [4/16 (25%) vs 9/32 (28%), p=NS] or between patients > 65 years and patients 65 years old (p=NS). Atrial thrombus was detected more frequently in patients with reduced left ventricular global systolic function than in those with normal function [7/14 (50%) vs 6/34 (17%), p<0.05]. In patients with spontaneous contrast echoes in the left atrium, thrombi were visualized more often than in those without spontaneous echoes [10/24 (41%) vs 3/24 (12%), p<0.05]. The finding of the atrial spontaneous contrast echoes was more frequent among patients with reduced left ventricular global systolic function [11/14 (78%) vs 13/34 (37%), p<0.02].We conclude that in hospitalized patients with non-rheumatic atrial fibrillation the prevalence of left atrial thrombus is high. Reduced left ventricular global systolic function identifies a subset of patients at high risk for formation of thrombus in the left atrium. 相似文献
66.
Diego Serraino Silvia Franceschi Renato Talamini Sergio Frustaci Carlo La Vecchia 《Cancer causes & control : CCC》1991,2(3):157-164
The role of socioeconomic and anthropometric indicators, tobacco, alcohol consumption, dietary habits, and medical history in the etiology of soft-tissue sarcoma (STS) was examined in a hospital-based case-control study, conducted in the Friuli-Venezia Giulia region of northeast Italy, between 1985 and 1990. A total of 88 STS cases (53 males and 35 females; median age: 52 years) and of 610 controls (306 males and 304 females; median age: 54 years) were interviewed. There were significant excess risks associated with a history of herpes zoster infection (odds ratio [OR]=2.4,95 percent confidence interval [CI]=1.1–5.3), chicken pox (OR=2.2, CI=1.2–4.3) and mumps in childhood (OR=2.0, CI=1.1–3.9). History of diabetes was also linked to a nonsignificant increase in STS risk (OR=1.8, CI=0.6–5.4), whereas exposure to radiation for diagnostic or therapeutic purposes was not related to the probability of developing STS. None of the investigated socioeconomic and anthropometric indicators seemed to affect STS risk; neither did tobacco smoking, nor consumption of alcohol, coffee, and tea beverages. Conversely, among the dietary habits investigated, a significant positive association emerged with an increasing frequency of consumption of dairy products (% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiiYdd9qrFfea0dXdf9vqai-hEir8Ve% ea0de9qq-hbrpepeea0db9q8as0-LqLs-Jirpepeea0-as0Fb9pgea% 0lrP0xe9Fve9Fve9qapdbaqaaeGacaGaaiaabeqaamaabaabcaGcba% Gaae4XdmaaCaaaleqabaGaaGOmaaaaaaa!3DA2!\[{\rm{\chi }}^2\]for trend=6.8, P<0.01) and oil (% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqefm0B1jxALjhiov2D% aebbfv3ySLgzGueE0jxyaibaiiYdd9qrFfea0dXdf9vqai-hEir8Ve% ea0de9qq-hbrpepeea0db9q8as0-LqLs-Jirpepeea0-as0Fb9pgea% 0lrP0xe9Fve9Fve9qapdbaqaaeGacaGaaiaabeqaamaabaabcaGcba% Gaae4XdmaaCaaaleqabaGaaGOmaaaaaaa!3DA2!\[{\rm{\chi }}^2\]for trend=4.3, P<0.05), while a negative association was seen for intake of whole grain bread and pasta (OR for highest cf lowest tertile=0.4, CI=0.2–0.9).Support for this project was contributed by the Italian Association for Cancer Research, Milan, and the Italian National Research Council (CNR Applied Project Oncology, Contract 87.01544.44). 相似文献
67.
Public Health System accepts "New Public Health" only in a theoretical way, since in the practice essential modifications to get "Health For All-2000" aims are not implemented. It is necessary to look "bridge-heads" that permit to introduce changes gradually to reorganize Health Services. In the present article, different alternatives are analyzed, all of them giving priority to the programmes that consider Health as a natural resource. These programmes can be "Governmental Programmes" so Health policies coming from the Health Department can be assumed by the others Public Administration Departments. 相似文献
68.
69.
de Diego Rodríguez E Roca Edreira A Martín García B Hernández Rodríguez R Portillo Martín JA Gutiérrez Baños JL Correas Gómez MA del Valle Schaan JI Villanueva Peña A Rado Velázquez MA Torío Sánchez B 《Actas urologicas espa?olas》2000,24(8):685-688
The schwannoma is a tumor resulting from the Schwann cells of neural shwath, being its retroperitoneal localization quite unusual. This tumor is clinically unspecified and in most of the cases it originates symptoms coming from the compression of the close structures when its localization is retroperitoneal. Its diagnosis is quite often fortuitous being confirmed by anatomopathological study afterwards. The treatment is surgical radical exeresis with subsequent followup. We report a new case of this uncommon retroperitoneal pathology in a female patient showing a nonspecific clinic. Two years after the surgery she remains asymptomatic without any radiological evidence of recidive. 相似文献