全文获取类型
收费全文 | 20160篇 |
免费 | 1394篇 |
国内免费 | 85篇 |
专业分类
耳鼻咽喉 | 189篇 |
儿科学 | 549篇 |
妇产科学 | 494篇 |
基础医学 | 2440篇 |
口腔科学 | 446篇 |
临床医学 | 2180篇 |
内科学 | 3821篇 |
皮肤病学 | 181篇 |
神经病学 | 2059篇 |
特种医学 | 668篇 |
外国民族医学 | 3篇 |
外科学 | 3319篇 |
综合类 | 246篇 |
一般理论 | 16篇 |
预防医学 | 1686篇 |
眼科学 | 502篇 |
药学 | 1529篇 |
中国医学 | 14篇 |
肿瘤学 | 1297篇 |
出版年
2023年 | 85篇 |
2022年 | 170篇 |
2021年 | 334篇 |
2020年 | 218篇 |
2019年 | 358篇 |
2018年 | 425篇 |
2017年 | 301篇 |
2016年 | 337篇 |
2015年 | 415篇 |
2014年 | 587篇 |
2013年 | 878篇 |
2012年 | 1358篇 |
2011年 | 1431篇 |
2010年 | 807篇 |
2009年 | 683篇 |
2008年 | 1353篇 |
2007年 | 1549篇 |
2006年 | 1323篇 |
2005年 | 1336篇 |
2004年 | 1398篇 |
2003年 | 1211篇 |
2002年 | 1195篇 |
2001年 | 202篇 |
2000年 | 162篇 |
1999年 | 209篇 |
1998年 | 269篇 |
1997年 | 236篇 |
1996年 | 185篇 |
1995年 | 151篇 |
1994年 | 145篇 |
1993年 | 144篇 |
1992年 | 145篇 |
1991年 | 134篇 |
1990年 | 115篇 |
1989年 | 102篇 |
1988年 | 90篇 |
1987年 | 105篇 |
1986年 | 98篇 |
1985年 | 80篇 |
1984年 | 91篇 |
1983年 | 98篇 |
1982年 | 99篇 |
1981年 | 101篇 |
1980年 | 88篇 |
1979年 | 73篇 |
1978年 | 74篇 |
1977年 | 61篇 |
1976年 | 68篇 |
1975年 | 64篇 |
1972年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Todd M. Koelling MD FACC Susan Joseph MD Keith D. Aaronson MD 《The Journal of heart and lung transplantation》2004,23(12):232-1422
BACKGROUND: The Heart Failure Survival Score (HFSS) has been previously shown to effectively risk-stratify patients under evaluation for heart transplantation. However, this model was developed before broad use of beta blockade. We hypothesized that the prognostic tool would retain its ability to risk stratify patients treated with beta-blockers. METHODS: We collected clinical data on 524 consecutive patients referred for heart transplantation from 1994 to 2001. Kaplan-Meier survival analysis and multivariable Cox regression analysis were performed with events defined as death, left ventricular assist device placement, or United Network of Organ Sharing 1 heart transplantation. RESULTS: Kaplan-Meier analysis of the patient population revealed effective discrimination by the survival score both for beta-blocker treated and untreated patients (both p <0.0001). Two-year event-free survival was 94% +/- 2% and 84% +/- 4% for beta-blocker and no beta-blocker patients in the low-risk HFSS strata. Cox proportional hazard modeling showed that HFSS strata (medium risk: HR 2.65, 95% CI 1.75-4.02, p <0.001; high risk: HR 5.51, 95% CI 3.64-8.33, p <0.001) and beta-blocker treatment (HR 0.45, 95% CI 0.31-0.64, p <0.001) were significant predictors of event-free survival. Receiver operating curves (area under the curve) for HFSS strata used to predict 2-year events were similar for beta-blocker treated (0.78 +/- 0.04) and untreated (0.80 +/- 0.03) patients. CONCLUSIONS: The HFSS provides effective risk stratification with or without beta-blocker therapy. Consideration of beta-blocker therapy with survival score strata improves outcome prediction in patients evaluated for heart transplantation. 相似文献
52.
Use of herbal supplements for chronic liver disease. 总被引:3,自引:0,他引:3
Cynthia Levy Leonard D Seeff Keith D Lindor 《Clinical gastroenterology and hepatology》2004,2(11):947-956
BACKGROUND & AIMS: Complementary and alternative medicine (CAM) is becoming popular among patients with liver disease. Although there is a growing body of evidence regarding potential mechanisms of action of these and other herbs, caution must be used to interpret the results of the few clinical trials available. Our goal was to discuss the biologic rationale for the use of specific herbs (silymarin, glycyrrhizin, sho-saiko-to, Phyllanthus amarus , Picrorrhiza kurroa , Compound 861, CH-100, and LIV.52) in the treatment of chronic liver diseases, as well as the evidence for their efficacy and adverse effects according to clinical trials. METHODS: Because of the relative paucity of clinical studies using herbs, every trial published in English was reviewed. RESULTS: Although many trials suggest that these herbs can decrease serum transaminase levels, the effects on hepatic histopathology and long-term survival are either poorly studied or conflicting. LIV.52 has been withdrawn from the market because of deleterious effects in patients with liver disease. CONCLUSIONS: Based on current evidence, we cannot recommend the use of herbal supplements for the routine treatment of any chronic liver disease and further well-designed clinical trials are necessary. 相似文献
53.
54.
Steven C. Cunningham M.D. Farin Kamangar M.D. M.P.H. Min P. Kim M.D. Sommer Hammoud Raqeeb Haque Anirban Maitra M.B.B.S. Elizabeth Montgomery M.D. Richard E. Heitmiller M.D. F.A.C.S. Michael A. Choti M.D. F.A.C.S. Keith D. Lillemoe M.D. F.A.C.S. John L. Cameron M.D. F.A.C.S. F.R.C.S. F.R.C.S.I. Charles J. Yeo M.D. F.A.C.S. Richard D. Schulick M.D. F.A.C.S. 《Journal of gastrointestinal surgery》2005,9(5):718-725
Gastric adenocarcinoma is the second leading cause of cancer death worldwide. In Western series, survival rates vary widely
and are generally lower than those reported from Eastern series. We performed a retrospective analysis of cases operated on
at the Johns Hopkins Hospital over the past 18 years and collected data on demographics, tumor characteristics, pathologic
stage, treatment methods, complications, survival time, and other relevant factors. Survival according to stage of disease,
Lauren tumor type, tumorlocation,time period, andadministration of adjuvant therapy wasanalyzed, andresultswerecompared with
those of other Western series. During this period, 436 patients with gastric adenocarcinoma underwent resection. We have shown
a statistically significant association between survival and margin status, stage of disease, and Lauren tumor type. Overall
5-year survival was 26%, and 5-year survival after R0 resection was 33%. No significant difference was detected between survival
and tumor location, time period of treatment, or administration of adjuvant therapy. Analysis of various Western series reveals
major differences between the cohorts under study, such as stage of disease, extent of resection, tumor type, and tumor location.
Many of the reported differences among Western series may be due to cohort differences, such as stage of disease, extent of
resection, tumor type, and tumor location. 相似文献
55.
Long-Term Clinical Outcomes Following Treatment of Actinic Keratosis with Imiquimod 5% Cream 总被引:2,自引:0,他引:2
Lee Peter K. MD PhD Harwell William B. MD † Loven Keith H. MD ‡ Phillips Tania J. MD § Whiting David A. MD res Kara L. MS # Lee James H. MD PhD # 《Dermatologic surgery》2005,31(6):659-664
BACKGROUND: The results from four phase III, randomized, vehicle-controlled studies showed that imiquimod 5% cream (imiquimod) was safe and effective in the treatment of actinic keratosis (AK). Patients applied imiquimod or vehicle cream to AK lesions on the face or balding scalp, dosing three times per week or two times per week for 16 weeks. OBJECTIVE: To obtain long-term safety follow-up data and estimate AK recurrence in patients who completely cleared their AK lesions in the treatment area at the 8-week post-treatment visit in the phase III studies. METHODS: One hundred forty-six patients from 30 study centers in the United States were evaluated for clinical evidence of AK, and safety data were collected. RESULTS: After a median follow-up period of 16 months, 24.7% (19 of 77) of the patients administered imiquimod three times per week and 42.6% (23 of 54) of the patients administered imiquimod two times per week had a recurrence of AK (the appearance of at least one AK lesion) in the original treatment area. The median number of AK lesions present was one lesion for both patients receiving imiquimod three times and those receiving imiquimod two times per week compared with a median of six lesions at baseline in the combined three times per week and two times per week phase III studies. There were no long-term safety issues, and the skin quality seen in the imiquimod-treated patients at the end of the phase III studies was maintained. CONCLUSION: One and a half years following treatment, imiquimod continued to provide a long-term clinical benefit in a majority of patients who experienced complete clearance of their AK lesions. 相似文献
56.
Martin C. Robson MD ; Diane M. Cooper PhD RN ; Rummana Aslam MD ; Lisa J. Gould MD PhD ; Keith G. Harding MBChB MRCGP FRCS ; David J. Margolis MD MSCE PhD ; Diane E. Ochs RN ; Thomas E. Serena MD ; Robert J. Snyder DPM ; David L. Steed MD ; David R. Thomas MD ; Laurel Wiersema-Bryant RN BC ANP 《Wound repair and regeneration》2008,16(2):147-150
57.
Hugh Devlin Kety Karayianni Anastasia Mitsea Reinhilde Jacobs Christina Lindh Paul van der Stelt Elizabeth Marjanovic Judith Adams Susan Pavitt Keith Horner 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(6):821-828
OBJECTIVES: Measurement of cortical thickness and subjective assessment of cortical porosity on panoramic radiographs are methods previously reported for diagnosing osteoporosis. The aims of this study were to determine the relative efficacy of the mandibular cortical index and cortical width in detecting osteoporosis, both alone and in combination, and to determine the optimal cortical width threshold for referral for additional osteoporosis investigation. STUDY DESIGN: Six hundred seventy-one postmenopausal women 45 to 70 years of age were recruited for this study. They received dual energy x-ray absorptiometry (DXA) scans of the left hip and lumbar spine (L1 to L4), and dental panoramic radiographic examinations of the teeth and jaws. Three observers separately assessed the mandibular cortical width and porosity in the mental foramen region of the mandible. Cortical width was corrected for magnification errors. Chi-squared automatic interaction detection analysis (CHAID) software was used (SPSS AnswerTree, version 3.1, SPSS Inc., Chicago, IL). RESULTS: Chi-squared automatic interaction detection analysis showed that the cortical porosity was a poorer predictor of osteoporosis than mandibular cortical width. For the 3 observers, a mandibular cortical width of <3 mm provided diagnostic odds ratios of 6.51, 6.09, and 8.04. The test is therefore only recommended in triage screening of individuals by using radiographs made for purposes other than osteoporosis. CONCLUSION: When evaluating panoramic radiographs, only those patients with the thinnest mandibular cortices (i.e., <3 mm) should be referred for further osteoporosis investigation. 相似文献
58.
Kalaichelvi Ganesalingam Ann Sanson Vicki Anderson Keith Owen Yeates 《Journal of the International Neuropsychological Society》2007,13(2):298-311
This study builds on our earlier investigation (see Ganesalingam et al., 2006). We showed previously that children with moderate to severe traumatic brain injuries (TBI) had poorer self-regulation and social and behavioral functioning than their uninjured peers and that self-regulation predicted significant variance in parent- and teacher-rated social and behavioral outcomes, regardless of the presence or absence of TBI. In this study, we examine self-regulation as a mediator of the relationship between TBI and the outcomes. Participants included 65 children with moderate to severe TBI and 65 children without TBI matched for age and gender. Participants were between 6 and 11 years of age. Children completed an assessment of cognitive, emotional, and behavioral self-regulation, and social and behavioral functioning. Mediation was assessed using a bootstrapping approach (a relatively novel statistical method for assessing specific indirect effects in models with multiple mediators). Analyses indicated that, after controlling for socioeconomic status (SES), aspects of self-regulation accounted for individual variation in the outcomes, and acted as a significant mediator of the effects of TBI on the outcomes. Self-regulatory deficits may reflect the relative vulnerability of the prefrontal cortex to TBI and may help account for post-injury difficulties in social and behavioral functioning. 相似文献
59.
Michael J. Gardner MD Sreevathsa Boraiah MD Keith D. Hentel MD David L. Helfet MD Dean G. Lorich MD 《The Journal of foot and ankle surgery》2007,46(4):256-260
Various patterns of ankle fractures that are not accounted for by common classification systems have been the subject of case reports. The first difficulty with these variant patterns is recognizing all associated pathology, followed by the successful application of stable fixation. The purpose of this study was to describe the common morphologic features and ligamentous injuries of a unique variant fracture pattern, as well as the surgical treatment technique and the short-term functional and radiographic outcomes. Of 121 consecutive unstable ankle fractures over a 2-year period, 7 patients were found to have a similar constellation of injuries around the ankle. A vertical shear fracture of the posteromedial tibial rim was the main feature. Six of the 7 also had a fracture of the posterior malleolus. On magnetic resonance imaging, the deltoid and posterior tibiofibular ligaments were intact in all cases. Fractures were treated with open anatomic reduction of the posteromedial and posterior fragments with antiglide plate fixation. All fractures healed at 2 months without loss of reduction, fixation failure, or surgical complications. The average American Academy of Orthopaedic Surgeons lower extremity score was 79 at an average of 8 months' follow-up. The common radiographic and morphologic features associated with this posteromedial fracture indicate that it likely occurs through a common mechanism that involves hyperplantarflexion. The characteristics of this fracture pattern have not been fully described previously, but this ankle fracture variant may occur in up to 6% of cases. Unstable ankle fractures should be evaluated carefully for evidence of posteromedial involvement so appropriate treatment may proceed. 相似文献
60.
Christopher L. Hansen Richard A. Goldstein Olakunle O. Akinboboye Daniel S. Berman Elias H. Botvinick Keith B. Churchwell C. David Cooke James R. Corbett S. James Cullom Seth T. Dahlberg Regina S. Druz Edward P. Ficaro James R. Galt Ravi K. Garg Guido Germano Gary V. Heller Milena J. Henzlova Mark C. Hyun Lynne L. Johnson April Mann Benjamin D. McCallister Robert A. Quaife Terrence D. Ruddy Senthil N. Sundaram Raymond Taillefer R. Parker Ward John J. Mahmarian 《Journal of nuclear cardiology》2007,14(6):e39-e60