全文获取类型
收费全文 | 5332篇 |
免费 | 368篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 94篇 |
妇产科学 | 74篇 |
基础医学 | 783篇 |
口腔科学 | 199篇 |
临床医学 | 429篇 |
内科学 | 1176篇 |
皮肤病学 | 71篇 |
神经病学 | 631篇 |
特种医学 | 154篇 |
外科学 | 974篇 |
综合类 | 39篇 |
一般理论 | 3篇 |
预防医学 | 269篇 |
眼科学 | 87篇 |
药学 | 339篇 |
中国医学 | 7篇 |
肿瘤学 | 364篇 |
出版年
2023年 | 37篇 |
2022年 | 65篇 |
2021年 | 153篇 |
2020年 | 94篇 |
2019年 | 131篇 |
2018年 | 173篇 |
2017年 | 136篇 |
2016年 | 133篇 |
2015年 | 146篇 |
2014年 | 243篇 |
2013年 | 245篇 |
2012年 | 431篇 |
2011年 | 449篇 |
2010年 | 227篇 |
2009年 | 216篇 |
2008年 | 378篇 |
2007年 | 350篇 |
2006年 | 312篇 |
2005年 | 306篇 |
2004年 | 240篇 |
2003年 | 250篇 |
2002年 | 232篇 |
2001年 | 44篇 |
2000年 | 26篇 |
1999年 | 41篇 |
1998年 | 69篇 |
1997年 | 36篇 |
1996年 | 40篇 |
1995年 | 35篇 |
1994年 | 30篇 |
1993年 | 25篇 |
1992年 | 28篇 |
1991年 | 36篇 |
1990年 | 25篇 |
1989年 | 24篇 |
1988年 | 22篇 |
1987年 | 25篇 |
1986年 | 27篇 |
1985年 | 37篇 |
1984年 | 26篇 |
1983年 | 20篇 |
1982年 | 19篇 |
1981年 | 13篇 |
1980年 | 20篇 |
1979年 | 15篇 |
1978年 | 11篇 |
1975年 | 8篇 |
1974年 | 9篇 |
1973年 | 13篇 |
1967年 | 12篇 |
排序方式: 共有5724条查询结果,搜索用时 218 毫秒
1.
Madan M. Rehani Emily R. Melick Raza M. Alvi Ruhani Doda Khera Salma Batool-Anwar Tomas G. Neilan Michael Bettmann 《European radiology》2020,30(4):1839-1846
To determine percent of patients without malignancy and ≤ 40 years of age with high cumulative radiation doses through recurrent CT exams and assess imaging appropriateness. From the cohort of patients who received cumulative effective dose (CED) of ≥ 100 mSv over a 5-year period, a sub-set was identified with non-malignant disease. The top 50 clinical indications leading to multiple CTs were determined. Clinical decision support (CDS) system scores were analyzed using a widely adopted standard of 1–3 (red) as “not usually appropriate,” 4–6 (yellow) “may or may not be appropriate,” and 7–9 (green) “usually appropriate.” Clinicians reviewed patient records to assess compliance with appropriate use criteria (AUC). 9.6% of patients in our series were with non-malignant conditions and 1.4% with age ≤ 40 years. CDS scores (rounded) were 2% red, 38% yellow, 27% green, and 33% unscored CTs. Clinical society guidelines for CT exams, wherever available, were followed in 87.5 to 100% of cases. AUCs were not available for several clinical indications as also referral guidelines for serial CT imaging. More than half of CT exams were unrelated to follow-up of a primary chronic disease. We are faced with a situation wherein patients in age ≤ 40 years require or are thought to require many CT exams over the course of a few years but the radiation risk creates concern. There is a fair number of conditions for which AUC are not available. Suggested solutions include development of CT scanners with lesser radiation dose and further development of appropriateness criteria. 相似文献
2.
3.
Sergue? O Fetissov Jarmila Hallman Ida Nilsson Ann-Kari Lefvert Lars Oreland Tomas H?kfelt 《Neuropsychopharmacology》2006,60(8):799-802
BACKGROUND: Altered stress response is characteristic for subjects with abnormal aggressive and antisocial behavior, but the underlying biological mechanisms are unclear. We hypothesized that autoantibodies (autoAbs) directed against several stress-related neurohormones may exist in aggressive subjects. METHODS: Using enzyme-linked immunosorbent assay, we studied whether autoAbs directed against corticotropin (ACTH), alpha-melanocyte-stimulating hormone (alpha-MSH), oxytocin, and vasopressin are present in serum of male subjects with conduct disorder and prisoners with history of violence. Healthy blood donors served as control subjects. RESULTS: Both conduct disorder and prisoners groups displayed strongly increased levels of ACTH-reactive immunoglobulin G (IgG) and immunoglobulin M (IgM) autoAbs compared with control subjects. Levels of oxytocin-reactive IgM autoAbs were slightly increased in both groups of aggressive subjects, whereas levels of vasopressin-reactive IgG and IgM autoAbs were lower only in conduct disorder. No differences in the levels of alpha-MSH-reactive autoAbs were found between aggressive and control subjects. CONCLUSIONS: High levels of ACTH-reactive autoAbs as well as altered levels of oxytocin- and vasopressin-reactive autoAbs found in aggressive subjects may interfere with the neuroendocrine mechanisms of stress and motivated behavior. Our data suggest a new biological mechanism of human aggressive behavior that involves autoAbs directed against several stress-related neurohormones. 相似文献
4.
5.
We would like to thank Professor Erdem Kasikcioglu for his interestin our article. In response to the initial question of why exhaustivephysical activity suppresses diastolic function, 相似文献
6.
Hospital outbreak caused by a carbapenem-resistant strain of Acinetobacter baumannii: patient prognosis and risk-factors for colonisation and infection 总被引:10,自引:0,他引:10
M. del Mar Tomas M. Cartelle S. Pertega A. Beceiro P. Llinares D. Canle F. Molina R. Villanueva J. M. Cisneros G. Bou 《Clinical microbiology and infection》2005,11(7):540-546
Between October 2001 and August 2002, 30 hospital patients became infected or colonised by a multiresistant (including to carbapenems) epidemic strain of Acinetobacter baumannii (AbMR) in a hospital outbreak. This study analysed the risk-factors associated with acquisition of this epidemic strain and investigated the prognosis of patients infected by AbMR, with the aim of elucidating factors which lead to mortality. A case-control study of the acquisition of AbMR in patients infected or colonised in the hospital outbreak was performed. Independent risk-factors leading to death were studied by logistic regression analysis. Multivariate analysis of the risk-factors for colonisation/infection with AbMR revealed an independent association with the presence of an arterial catheter (OR, 1.13; 95% CI, 1.03-1.25) and administration of imipenem as monotherapy (OR, 11.12; 95% CI, 2.33-53.09). Multivariate analysis of the prognostic features leading to mortality revealed a significant association with hypotension or shock (OR, 24.63; 95% CI, 1.56-387.56) at the time of bacterial isolation. 相似文献
7.
Comparison of right colon, left colon, and rectal carcinoma 总被引:3,自引:0,他引:3
Three hundred fifteen cases of adenocarcinoma were analyzed for differences between lesions in the right colon, left colon, and rectum for the period 1978 to 1983. The right colon cancers accounted for 1/3 of the cases and were associated with a higher incidence of anemia. The incidence of obstruction was the same between the right and left colon but lower for the rectal lesions. Left colon and rectal cancers had a higher incidence of gross bleeding than right colon cancers, but all had a high rate of occult blood in the stool. The Duke stage of the lesions, which was similar throughout the colon and rectum, is a reliable prognostic indicator. 相似文献
8.
Retrospective review of the preoperative biliary and gastrointestinal evaluation for gastric bypass surgery 总被引:1,自引:0,他引:1
Vincent W. Vanek M.D. C.N.S.P. F.A.C.S. Michele Catania R.N. B.S.N. Kimberly Triveri R.D. L.D. Robert W. Woodruff Jr M.D. 《Surgery for obesity and related diseases》2006,2(1):839-22
BACKGROUND: The purpose of this study was to analyze the frequency and results of preoperative biliary and gastrointestinal (GI) evaluation of patients undergoing Roux-en-Y gastric bypass (RYGB). METHODS: Retrospective review of the preoperative evaluation of 144 consecutive RYGB patients. RESULTS: Cholecystectomy had already been performed in 43 (30%) patients; 22% of those patients with an intact gallbladder had cholelithiasis. Ten patients (7%) had an upper GI x-ray (UGI), and 94 patients (65%) had an esophagogastroduodenoscopy (EGD). Abnormalities were found in 40% of the UGIs and 84% of the EGDs. A total of 96 patients (67%) were tested for Helicobacter pylori; 11% were positive. Twenty-one patients (15%) underwent preoperative colonoscopy; 48% were abnormal, but most of the abnormalities were not clinically significant. Three patients had barium enema x-ray, which was normal in all cases. CONCLUSIONS: The preoperative biliary and GI evaluation of bariatric surgery patients should include a routine ultrasound of the gallbladder. Routine preoperative EGD will detect a significant number of abnormalities that should be treated, but should rarely alter the bariatric surgical procedure or result in denial of bariatric surgery. Many abnormalities will be asymptomatic. Patients should be routinely screened for H. pylori and, if positive, treated before bariatric surgery. Lower GI evaluation should be performed selectively based on the patient's symptoms, physical findings, and guidelines for colorectal cancer and polyp screening. 相似文献
9.
10.
Dr. Hajo Dirk Weitmann Tomas Hendrik Knocke Claudia Waldhäusl Richard Pötter 《Strahlentherapie und Onkologie》2006,182(2):86-95
BACKGROUND: In advanced vaginal recurrences of cervical and endometrial carcinomas therapeutic options are rare because of preceding therapy. PATIENTS AND METHODS: 23 patients developing advanced vaginal recurrences of cervical and endometrial carcinomas were included. 15 patients started with external-beam therapy to the pelvis and eight patients after preceding radiotherapy underwent brachytherapy alone. All patients had ultrasound-guided implantation of transvaginal or transperineal interstitial needles for brachytherapy. Median prescribed total dose was 64 Gy. RESULTS: 18 patients (78%) achieved complete remission. Six patients are alive without tumor and one with tumor after a median follow-up of 64 months. 14 patients died of tumor and two of intercurrent disease. 5-year disease-specific survival and local control rate were 43% and 47%, respectively, in patients with complete remission. Univariate analysis found time to relapse > 2 years, initial diameter < or = 4 cm, initial volume < 15 cm(3), no extension to the pelvic side wall, volume before brachytherapy < 7.5 cm(3), brachytherapy coverage index > 0.8, and prescribed total dose > 64 Gy being positive predictors for local control and survival. CONCLUSION: The use of ultrasound guidance for placement of interstitial needles in template-based brachytherapy of advanced recurrent gynecologic malignancies is a feasible, safe, and cheap method with encouraging results. Today, ultrasound imaging can be also used to some extent for treatment planning which requires further development. Patient- and treatment-related prognostic factors can be defined. 相似文献