全文获取类型
收费全文 | 2243篇 |
免费 | 77篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 69篇 |
妇产科学 | 62篇 |
基础医学 | 188篇 |
口腔科学 | 190篇 |
临床医学 | 524篇 |
内科学 | 324篇 |
皮肤病学 | 30篇 |
神经病学 | 178篇 |
特种医学 | 127篇 |
外科学 | 279篇 |
综合类 | 30篇 |
预防医学 | 119篇 |
眼科学 | 23篇 |
药学 | 116篇 |
中国医学 | 18篇 |
肿瘤学 | 72篇 |
出版年
2023年 | 11篇 |
2022年 | 22篇 |
2021年 | 35篇 |
2020年 | 29篇 |
2019年 | 44篇 |
2018年 | 43篇 |
2017年 | 27篇 |
2016年 | 30篇 |
2015年 | 52篇 |
2014年 | 59篇 |
2013年 | 104篇 |
2012年 | 133篇 |
2011年 | 142篇 |
2010年 | 107篇 |
2009年 | 99篇 |
2008年 | 111篇 |
2007年 | 123篇 |
2006年 | 109篇 |
2005年 | 81篇 |
2004年 | 74篇 |
2003年 | 66篇 |
2002年 | 67篇 |
2001年 | 39篇 |
2000年 | 29篇 |
1999年 | 43篇 |
1998年 | 98篇 |
1997年 | 88篇 |
1996年 | 81篇 |
1995年 | 67篇 |
1994年 | 52篇 |
1993年 | 57篇 |
1992年 | 19篇 |
1991年 | 26篇 |
1990年 | 27篇 |
1989年 | 22篇 |
1988年 | 34篇 |
1987年 | 12篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1984年 | 15篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1971年 | 2篇 |
1958年 | 2篇 |
排序方式: 共有2363条查询结果,搜索用时 15 毫秒
81.
Manoel J. Teixeira Massako Okada Ana Sofia Cueva Moscoso Mariana Yumi Takahashi Puerta Lin T. Yeng Ricardo Galhardoni Sérgio Tengan Daniel Ciampi de Andrade 《Clinics (S?o Paulo, Brazil)》2013,68(7):1057-1060
OBJECTIVE:
This research was designed as a pilot proof-of-concept study to evaluate the use of low-dose methadone in post-herpetic neuralgia patients who remained refractory after first and second line post-herpetic neuralgia treatments and had indications for adding an opioid agent to their current drug regimens.METHODS:
This cross-over study was double blind and placebo controlled. Ten opioid naïve post-herpetic neuralgia patients received either methadone (5 mg bid) or placebo for three weeks, followed by a 15-day washout period and a second three-week treatment with either methadone or placebo, accordingly. Clinical evaluations were performed four times (before and after each three-week treatment period). The evaluations included the visual analogue scale, verbal category scale, daily activities scale, McGill pain questionnaire, adverse events profile, and evoked pain assessment. All patients provided written informed consent before being included in the study. ClinicalTrials.gov: NCT01752699RESULTS:
Methadone, when compared to placebo, did not significantly affect the intensity of spontaneous pain, as measured by the visual analogue scale. The intensity of spontaneous pain was significantly decreased after the methadone treatment compared to placebo on the category verbal scale (50% improved after the methadone treatment, none after the placebo, p = 0.031). Evoked pain was reduced under methadone compared to placebo (50% improved after the methadone treatment, none after the placebo, p = 0.031). Allodynia reduction correlated with sleep improvement (r = 0.67, p = 0.030) during the methadone treatment. The side effects profile was similar between both treatments.CONCLUSIONS:
Methadone seems to be safe and efficacious in post-herpetic neuralgia. It should be tried as an adjunctive treatment for post-herpetic neuralgia in larger prospective studies. 相似文献82.
83.
In 260 asbestos-exposed individuals evaluated by means of computed tomography (CT), 43 unsuspected pulmonary masses were found in 27 individuals. The masses included fissural pleural plaques (n = 10), dense fibrotic bands (n = 3), round atelectasis (n = 11), carcinomas (n = 3), and other presumed benign masses (n = 16). The most helpful features in the diagnosis of rounded atelectasis with CT were (a) contiguity to areas of diffuse pleural thickening, (b) a lentiform or wedge-shaped outline, (c) evidence of volume loss in the adjacent lung, and (d) a characteristic "comet tail" of vessels and bronchi sweeping into the margins of the mass. Less advanced areas of focal atelectasis had fewer classic features. Intrafissural pleural plaques were readily identified with high-resolution CT. In asbestos-related masses, the demonstration of stability over time is necessary. Careful interpretation of CT and high-resolution CT features and close surveillance can obviate the need for biopsy in the majority of instances. 相似文献
84.
A Gulsahi CS Paksoy S Ozden NO Kucuk ARI Cebeci Y Genc 《Dento maxillo facial radiology》2010,39(5):284-289
Objectives
The aim of this study was to evaluate maxillary, mandibular and femoral neck bone mineral density using dual energy X-ray absorptiometry (DXA) and to determine any correlation between the bone mineral density of the jaws and panoramic radiomorphometric indices.Methods
49 edentulous patients (18 males and 31 females) aged between 41 and 78 years (mean age 60.2 ± 11.04) were examined by panoramic radiography. Bone mineral density (BMD) of the jaws and femoral neck was measured with a DXA; bone mineral density was calculated at the anterior, premolar and molar regions of the maxilla and mandible.Results
The mean maxillary molar BMD (0.45 g cm−2) was significantly greater than the maxillary anterior and premolar BMD (0.31 g cm−2, P < 0.05). Furthermore, the mean mandibular anterior and premolar BMD (1.39 g cm−2 and 1.28 g cm−2, respectively) was significantly greater than the mean mandibular molar BMD (1.09 g cm−2, P < 0.01). Although BMD in the maxillary anterior and premolar regions were correlated, BMD in all the mandibular regions were highly correlated. Maxillary and mandibular BMD were not correlated with femoral BMD. In addition, mandibular cortical index (MCI) classification, mental index (MI) or panoramic mandibular index (PMI) values were not significantly correlated with the maxillary and mandibular BMDs (P > 0.05).Conclusions
The BMD in this study was highest in the mandibular anterior region and lowest in the maxillary anterior and premolar regions. The BMD of the jaws was not correlated with either femoral BMD or panoramic radiomorphometric indices. 相似文献85.
We evaluated the hematologic, rheologic, and biochemical features of erythrocytes obtained from 10 relatives of a 5-yr-old black female with hereditary pyropoikilocytosis (HPP) and severe hemolytic anemia. Erythrocyte morphology was normal in the father and five other relatives, but ghost mechanical fragility and drug-induced red cell endocytosis were increased, as was the percentage of spectrin dimers noted on 3.2% nondenaturing PAGE of spectrin extracts. Identical changes were also noted in the mother and her sister, whose erythrocytes were elliptocytic and exhibited morphological changes upon heating to 45 degrees-48 degrees C (normal 49 degrees). The two other family members were normal in every respect. SDS-PAGE analysis of membrane proteins demonstrated diminished amounts of spectrin in HPP erythrocytes, but was normal in other family members. A diffuse band (mol wt 575,000-665,000), composed entirely of spectrin, was apparent adjacent to the dimer region on nondenaturing PAGE of spectrin extracts from the propositus, mother, and aunt. In this family, HPP appears to have resulted from compound heterozygosity for two distinct genetic abnormalities (reflected by the differences between elliptocytic and nonelliptocytic carriers). Although the membrane abnormalities in carriers did not result in hemolytic anemia, they were of sufficient magnitude to allow the detection of the carrier state. 相似文献
86.
Motor unit number index (MUNIX) in myopathic disorders: Clinical correlations and potential pitfalls
87.
Sampaio MC de Oliveira ZN Machado MC dos Reis VM Vilela MA 《Pediatric dermatology》2008,25(2):163-167
Abstract: Discoid lupus erythematosus is much less frequent and studied in children. We undertook a retrospective study of 34 children less than 16 years of age with this disease, seen over a period of 9 years. A female predominance of 2:1 was found. An association between discoid lupus erythematosus and systemic lupus erythematosus was observed in 23.5% of patients, a higher proportion compared to adult discoid lupus erythematosus. Disseminated lesions were much more frequent in patients with criteria for systemic lupus erythematosus (87.5% vs 34%), suggesting that it could be associated with a worse prognosis. Histologic findings were similar to those observed in adult discoid lupus erythematosus. 相似文献
88.
Introduction
The aim of this study was to evaluate the effectiveness of different irrigant agitation techniques on smear layer removal in curved root canals.Methods
Mesiobuccal canals of 62 extracted lower molars with a curvature of 33 degrees were used and instrumented up to ProTaper F2. The samples were divided into 3 experimental groups according to the final irrigation: conventional irrigation, ultrasonic irrigation, and sonic irrigation by using the EndoActivator system. The control group was composed of 2 specimens without any final irrigation. In all of the experimental groups, 5 mL of 17% ethylenediaminetetraacetic acid was used for 1 minute, and 5 mL of 2.5% NaOCl was used for 30 seconds. The analysis of the apical region was performed via scanning electron microscopy by 3 examiners. The data were submitted to the Kruskal-Wallis and Dunn tests (P < .05).Results
The activation systems removed significantly more smear layer than did conventional irrigation.Conclusions
Sonic and ultrasonic irrigation resulted in better removal of the smear layer in the apical third of curved root canals than did conventional irrigation. 相似文献89.
Fuad Jacob Abi Rached-Junior Aline Evangelista Souza-Gabriel Edson Alfredo Carlos Eduardo Saraiva Miranda Yara Teresinha Correa Silva-Sousa Manoel Damião Sousa-Neto 《Journal of endodontics》2009,35(2):251-255
This study evaluated in vitro the bond strength of Epiphany sealer prepared with resinous solvent of Epiphany system (Thinning resin) by using a push-out test. Forty maxillary canines were sectioned transversally below the cementoenamel junction to provide 4-mm-thick dentin disks that were centered in aluminum rings and embedded in acrylic resin. Root canals were prepared with tapered diamond bur. Intraradicular dentin was treated with 1% NaOCl for 30 minutes, 17% ethylenediaminetetraacetic acid for 5 minutes, and flushed with distilled water for 1 minute. The specimens were randomly distributed into 4 groups (n = 10) according to the filling material: GI, Epiphany without photoactivation; GII, Epiphany prepared with solvent without photoactivation; GIII, Epiphany followed by photoactivation; and GIV, Epiphany prepared with solvent followed by photoactivation. After the setting time, the specimens were submitted to the push-out test. The highest mean value (14.91 ± 2.82 MPa) was obtained with Epiphany prepared with solvent followed by photoactivation (GIV), which was statistically different (P < .01) from the other groups. Groups I (8.15 ± 2.47 MPa), II (9.46 ± 2.38 MPa), and III (9.80 ± 2.51 MPa) had inferior bond strength values and were statistically similar among themselves (P > .01). The resinous solvent of Epiphany system increased the bond strength of Epiphany sealer to dentin walls when followed by photoactivation. 相似文献
90.
Uenis Tannuri Maria M. Santos Ana Cristina A. Tannuri Nelson E. Gibelli Airton Moreira Francisco C. Carnevale Ali A. Ayoub João G. Maksoud-Filho Wagner C. Andrade Manoel C.P. Velhote Marcos M. Silva Maria L. Pinho-Apezzato Helena T. Miyatani Raimundo R.N. Guimarães 《Journal of pediatric surgery》2011,46(7):1379-1384