全文获取类型
收费全文 | 2204篇 |
免费 | 128篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 33篇 |
妇产科学 | 78篇 |
基础医学 | 162篇 |
口腔科学 | 65篇 |
临床医学 | 189篇 |
内科学 | 641篇 |
皮肤病学 | 30篇 |
神经病学 | 262篇 |
特种医学 | 81篇 |
外科学 | 346篇 |
综合类 | 7篇 |
预防医学 | 66篇 |
眼科学 | 96篇 |
药学 | 116篇 |
肿瘤学 | 149篇 |
出版年
2024年 | 5篇 |
2023年 | 41篇 |
2022年 | 70篇 |
2021年 | 127篇 |
2020年 | 60篇 |
2019年 | 83篇 |
2018年 | 96篇 |
2017年 | 72篇 |
2016年 | 77篇 |
2015年 | 80篇 |
2014年 | 105篇 |
2013年 | 131篇 |
2012年 | 188篇 |
2011年 | 180篇 |
2010年 | 89篇 |
2009年 | 104篇 |
2008年 | 134篇 |
2007年 | 103篇 |
2006年 | 120篇 |
2005年 | 99篇 |
2004年 | 91篇 |
2003年 | 75篇 |
2002年 | 80篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 15篇 |
1998年 | 7篇 |
1997年 | 11篇 |
1996年 | 6篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有2351条查询结果,搜索用时 31 毫秒
961.
Orlandi I Camiciottoli G Diciotti S Bartolucci M Cavigli E Nacci F Matucci-Cerinic M Villari N Mascalchi M 《Journal of computer assisted tomography》2006,30(5):823-827
OBJECTIVE: To correlate lung density measurements with the results of visual assessment of thin-section computed tomography (CT) and of pulmonary function tests (PFT) in Systemic Sclerosis (SSc). METHODS: Thirty-nine SSc patients underwent sequential thin-section CT and spiral low-dose whole-lung acquisitions. The thin-section CT scans were evaluated with a dedicated visual scale. Mean lung density, skewness, and kurtosis were calculated from the lung density histogram. In addition from the spiral low-dose acquisition, the lung volume was computed. The visual score, the densitometric parameters, and the lung volume were correlated with the PFT. RESULTS: Mean lung density, skewness, and kurtosis computed from thin-section (R = 0,66; R = -0,74; R = -0,75) and low-dose volumetric (R = 0,72; R = -0,71; R = -0,71) CT and the lung volume (R = -0.54) correlated with the visual score. Densitometric values and lung volume consistently better correlated with PFT than the visual score. CONCLUSIONS: In SSc the histogram results are more closely correlated to PFT than the visual score. The low-dose spiral CT seems ideal for longitudinal studies. 相似文献
962.
Crane PK Gibbons LE Jolley L van Belle G Selleri R Dalmonte E De Ronchi D 《International psychogeriatrics / IPA》2006,18(3):505-515
BACKGROUND: Differential item functioning (DIF) exists when test item responses by members of different demographic groups are statistically different when controlling for ability. DIF may indicate item bias. Our objective was to determine whether items from the Italian Mini-mental State Examination (MMSE) had DIF related to educational attainment, age, gender and occupation. We were also interested in exploring the significance of DIF in screening tests. METHODS: In a two-stage study from Granarolo, Italy, residents over age 61 (n = 495) were evaluated with the Italian MMSE. Those with MMSE scores of 28 or lower were further evaluated for dementia. MMSE results were coded in 10 item bundles. We used ordinal logistic regression to determine whether item bundles had DIF. RESULTS: Six of the 10 MMSE item bundles had DIF in educational attainment subgroups. Four of these six bundles also had DIF related to age. Items that required literacy were much harder for those with lower educational attainment. CONCLUSIONS: DIF related to education appeared at as few as 3 years of formal schooling. These findings suggest cautious interpretation of data from studies using the Italian MMSE in populations with heterogeneous educational backgrounds. DIF is especially troublesome for two-stage studies that use screening tests. 相似文献
963.
This study reports the 5-year clinical and radiological outcomes of a simple arthroscopic-assisted technique for Schatzker types II and III tibial plateau fractures, without bone grafting. Forty six patients (46% males, 54% females, average age 48 years, SD 13.6 years), with tibial plateau fractures Schatzker types II (41%) and III (59%), underwent an arthroscopic-assisted technique conceived to use a compacted cancellous bone graft, taken from the medial metaphyseal side of the tibia, and a percutaneous fixation. The patients were prospectively followed-up at 1, 3 and 5 years from surgery. Independent assessments were carried out using Knee Society Score, HSS score and Rasmussen's clinical and radiological scores. At 5-year follow-up patients underwent a weight-bearing radiograph of both limbs. At last follow-up evaluation Knee Score (average 93.2, SD 7.7) was excellent in 37 patients (80%), good in six (13%), fair in three (7%). Function Score (average 94.8, SD 8.51) was excellent in 38 patients (83%), good in five (11%), fair in three (6%). HSS score (average 93.4, SD 8.23) was excellent in 41 patients (89%), good in five (11%). The average Rasmussen clinical score was 28.2 (SD 1.4). The radiological Rasmussen score was excellent in five patients (11%), good in 39 (85%) and fair in two (4%). In the weight-bearing radiographs a valgus deviation was present in four patients (8.7%). This technique has outcomes encouraging and comparable to the results of other techniques that use either iliac crest graft or bone substitutes. 相似文献
964.
Prevalence and correlates of pulmonary emphysema in smokers and former smokers. A densitometric study of participants in the ITALUNG trial 总被引:1,自引:1,他引:0
Camiciottoli G Cavigli E Grassi L Diciotti S Orlandi I Zappa M Picozzi G Pegna AL Paci E Falaschi F Mascalchi M 《European radiology》2009,19(1):58-66
We assessed with computed tomography (CT) densitometry the prevalence of emphysema in 266 (175 men and 91 women; mean age
64 ± 4 years) smokers and former smokers enrolled in the ITALUNG trial of lung cancer screening with low-dose thin-slice CT.
Whole-lung volume and the relative area at −950 Hounsfield units (RA950) and mean lung attenuation (MLA) in 1 of every 10 slices (mean, 24 slices per subject) were measured. Lung volume, MLA and
RA950 significantly correlated each other and with age. Average RA950 >6.8% qualifying for emphysema was present in 71 (26.6%)
of 266 subjects, with a higher prevalence in men than in women (30.3% vs 19.8%; p = 0.003). Only in smokers was a weak (r = 0.18;
p = 0.05) correlation between RA950 and packs/year observed. In multiple regression analysis, the variability of RA950 (R2 = 0.24)
or MLA (R2 = 0.34) was significantly, but weakly explained by age, lung volume and packs/year. Other factors besides smoking
may also have a significant role in the etiopathogenesis of pulmonary emphysema.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
965.
Focosi D Maggi F Pistolesi D Benedetti E Papineschi F Galimberti S Ceccherini-Nelli L Petrini M 《Leukemia research》2009,33(4):556-560
Hemorrhagic cystitis is a common complication in hematopoietic stem cell transplant recipients. We report here a case of severe BKV-associated hemorrhagic cystitis who did not respond to intravenous cidofovir. Overt hematuria successfully resolved after a few days on hyperbaric oxygen and intravesical instillations of cidofovir, while BK viruria dropped after a few weeks and remained low. We review the literature for therapeutic options in hemorrhagic cystitis and try to explain how hyperbaric oxygen stimulates mucosal repair in the urinary bladder. 相似文献
966.
Raffaele Parrozzani Barbara Boccassini Valentina De Belvis Pietro Paolo Radin Edoardo Midena 《Acta ophthalmologica. Supplement》2009,87(7):789-792
Purpose: To evaluate prospectively, on a long‐term range, the clinical outcomes of transpupillary thermotherapy (TTT) as primary treatment of selected choroidal melanoma. Methods: Seventy‐seven eyes of 77 patients affected by small posterior choroidal melanoma were treated with TTT as a sole treatment, using an infrared diode laser at 810 nm according to a standard procedure. Follow‐up was longer than 36 months. Results: Seventeen tumours (22%) were parapapillary (PP) and 60 tumours (78%) were non‐parapapillary (NPP) in location. Mean follow‐up was 55.2 ± 17.9 months in PP tumours and 44.3 ± 23.7 months in NPP tumours. Thirteen (76%) PP tumours and 55 (92%) NPP tumours regressed (P > 0.05). Nine tumours recurred: seven were retreated using Iodine‐125 brachytherapy and two were enucleated (both parapapillary). Four patients (5%) developed liver metastasis and died during follow‐up. Tumour thickness was found to be predictive of recurrence (odds ratio: 4.3). Complications were found in 20 eyes (26%): macular pucker in 11 (14%), macular oedema in three (4%), retinal vein occlusion in six (8%), vitreous and subretinal haemorrhage in two (3%) and neovascular glaucoma in three (4%). PP tumours had more local complications (but this was not statistically significant; P > 0.05). Complications appeared more frequently in tumours treated with more than one TTT session (P = 0.01), and time‐risk to develop intraocular complications seems longer in the PP group, without reaching statistical significance (P = 0.07). Conclusion: TTT may be a clinically effective method for conservative treatment of selected, non‐parapapillary, small posterior choroidal melanoma. 相似文献
967.
968.
Oussoultzoglou E Panaro F Rosso E Zeca I Bachellier P Pessaux P Jaeck D 《World journal of surgery》2008,32(9):1968-1973
BACKGROUND: Postoperative hypocalcemia is the most common complication after thyroidectomy. New surgical devices have been propose to achieve vessel sealing and hemostasis. However, the risk of parathyroid glands damage has not been fully elucidated. This prospective study was designed to evaluate the severity of hypocalcemia after total thyroidectomy by using two different sealing devices. METHODS: Between January 2005 and December 2006, 86 patients underwent total thyroidectomy by using BiClamp((R)) (n = 46) or LigaSure((R)) (n = 40) devices in our institution. The severity of postoperative hypocalcemia was analyzed. RESULTS: No mortality or recurrent laryngeal nerve palsy was observed. Patients characteristics were similar in both groups. The mean operation time was significantly shorter in the BiClamp group (142 +/- 35 minutes versus 170 +/- 57 minutes, P = 0.023). Eleven patients had symptomatic hypocalcemia. Hypocalcemia (< 2 mmol/l) at postoperative day 1 was more frequent in the LigaSure group than in the BiClamp group (P = 0.034). Significantly more patients in the LigaSure group required oral calcium supplementation than in the BiClamp group (67.5% versus 34.7% respectively; P = 0.002). CONCLUSION: The present prospective study suggests that total thyroidectomy can be performed safely with both surgical devices. However, BiClamp reduced the operative time and the severity of postoperative hypocalcemia. 相似文献
969.
Paul Madaj Dong Li Rine Nakanishi Daniele Andreini Gianluca Pontone Edoardo Conte Rachael O'Rourke Christian Hamilton-Craig Manojna Nimmagadda Nicholas Kim Badiha Fatima Christopher Dailing Kashif Shaikh Chandana Shekar Ju Hwan Lee Matthew J. Budoff 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》2022,49(2)
Computed tomographic coronary artery calcium scanning enables cardiovascular risk stratification; however, exposing patients to high radiation levels is an ongoing concern. New-generation computed tomographic systems use lower radiation doses than older systems do. To quantify comparative doses of radiation exposure, we prospectively acquired images from 220 patients with use of a 64-slice GE LightSpeed VCT scanner (control group, n=110) and a 256-slice GE Revolution scanner (study group, n=110). The groups were matched for age, sex, and body mass index; statistical analysis included t tests and linear regression.The mean dose-length product was 21% lower in the study group than in the control group (60.2 ± 27 vs 75.9 ± 22.6 mGy·cm; P <0.001) and also in each body mass index subgroup. Similarly, the mean effective radiation dose was 21% lower in the study group (0.84 ± 0.38 vs 1.06 ± 0.32 mSv) and lower in each weight subgroup. After adjustment for sex, women in the study group had a lower dose-length product (50.4 ± 23.4 vs 64.7 ± 27.6 mGy·cm) than men did and received a lower effective dose (0.7 ± 0.32 vs 0.9 ± 0.38 mSv) (P=0.009). As body mass index and waist circumference increased, so did doses for both scanners.Our study group was exposed to radiation doses lower than the previously determined standard of 1 mSv, even after adjustment for body mass index and waist circumference. In 256-slice scanning for coronary artery calcium, radiation doses are now similar to those in lung cancer screening and mammography. 相似文献
970.
Jonathan E Suk Anastasia Pharris Julien Beaut Edoardo Colzani Howard Needham John Kinsman Rene Niehus Rok Grah Ajibola Omokanye Diamantis Plachouras Agoritsa Baka Bastian Prasse Frank Sandmann Ettore Severi Erik Alm Emma Wiltshire Bruno Ciancio 《Euro surveillance : bulletin européen sur les maladies transmissibles = European communicable disease bulletin》2022,27(17)
Many countries, including some within the EU/EEA, are in the process of transitioning from the acute pandemic phase. During this transition, it is crucial that countries’ strategies and activities remain guided by clear COVID-19 control objectives, which increasingly will focus on preventing and managing severe outcomes. Therefore, attention must be given to the groups that are particularly vulnerable to severe outcomes of SARS-CoV-2 infection, including individuals in congregate and healthcare settings. In this phase of pandemic management, a strong focus must remain on transitioning testing approaches and systems for targeted surveillance of COVID-19, capitalising on and strengthening existing systems for respiratory virus surveillance. Furthermore, it will be crucial to focus on lessons learned from the pandemic to enhance preparedness and to enact robust systems for the preparedness, detection, rapid investigation and assessment of new and emerging SARS-CoV-2 variants. Filling existing knowledge gaps, including behavioural insights, can help guide the response to future resurgences of SARS-CoV-2 and/or the emergence of other pandemics. Finally, ‘vaccine agility’ will be needed to respond to changes in people’s behaviours, changes in the virus, and changes in population immunity, all the while addressing issues of global health equity. 相似文献