全文获取类型
收费全文 | 31634篇 |
免费 | 6810篇 |
国内免费 | 135篇 |
专业分类
耳鼻咽喉 | 819篇 |
儿科学 | 1038篇 |
妇产科学 | 971篇 |
基础医学 | 1677篇 |
口腔科学 | 2888篇 |
临床医学 | 5222篇 |
内科学 | 7582篇 |
皮肤病学 | 593篇 |
神经病学 | 3018篇 |
特种医学 | 1478篇 |
外科学 | 5041篇 |
综合类 | 248篇 |
现状与发展 | 12篇 |
一般理论 | 65篇 |
预防医学 | 3496篇 |
眼科学 | 435篇 |
药学 | 684篇 |
1篇 | |
中国医学 | 8篇 |
肿瘤学 | 3303篇 |
出版年
2024年 | 164篇 |
2023年 | 1110篇 |
2022年 | 404篇 |
2021年 | 732篇 |
2020年 | 1274篇 |
2019年 | 597篇 |
2018年 | 1441篇 |
2017年 | 1367篇 |
2016年 | 1594篇 |
2015年 | 1657篇 |
2014年 | 2094篇 |
2013年 | 2604篇 |
2012年 | 1149篇 |
2011年 | 1089篇 |
2010年 | 1557篇 |
2009年 | 2116篇 |
2008年 | 1152篇 |
2007年 | 910篇 |
2006年 | 1054篇 |
2005年 | 860篇 |
2004年 | 688篇 |
2003年 | 667篇 |
2002年 | 616篇 |
2001年 | 771篇 |
2000年 | 649篇 |
1999年 | 707篇 |
1998年 | 597篇 |
1997年 | 584篇 |
1996年 | 643篇 |
1995年 | 493篇 |
1994年 | 387篇 |
1993年 | 355篇 |
1992年 | 485篇 |
1991年 | 460篇 |
1990年 | 407篇 |
1989年 | 448篇 |
1988年 | 394篇 |
1987年 | 419篇 |
1986年 | 410篇 |
1985年 | 367篇 |
1984年 | 273篇 |
1983年 | 311篇 |
1982年 | 251篇 |
1981年 | 188篇 |
1980年 | 185篇 |
1979年 | 240篇 |
1978年 | 170篇 |
1977年 | 146篇 |
1976年 | 138篇 |
1973年 | 132篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
101.
102.
103.
104.
Can Electrocardiographic Criteria Predict Adverse Cardiac Events and Positive Cardiac Markers? 总被引:5,自引:0,他引:5
Andra L. Blomkalns MD Christopher J. Lindsell PhD Abhinav Chandra MD Mary E. Osterlund MD W. Brian Gibler MD Charles V. Pollack MS MD Brian R. Tiffany MD PhD Judd E. Hollander MD James W. Hoekstra MD 《Academic emergency medicine》2003,10(3):205-210
OBJECTIVES: To determine electrocardiogram (ECG) predictors of positive cardiac markers and short-term adverse cardiac events in an undifferentiated chest pain population presenting to emergency departments (EDs). The authors hypothesized that specific ECG findings, other than those previously identified in higher-risk populations, would be predictive of cardiac outcomes and positive cardiac markers. METHODS: This study used data from a prospectively collected, retrospectively analyzed Internet-based data registry of undifferentiated chest pain patients (i*trACS). Logistic regression modeling was performed to determine the ECG findings that were predictive of 1) positive cardiac markers and 2) short-term adverse cardiac events. RESULTS: ST-segment elevation (STE), ST-segment depression (STD), pathological Q-waves (PQW), and T-wave inversion were associated with increased odds of percutaneous coronary intervention or catheterization, myocardial infarction, or coronary artery bypass grafting. The odds of creatine kinase-MB (CK-MB) measuring positive were increased if STE, STD, or PQW were present [odds ratio (OR) 2.495, 2.582, and 1.295, respectively]. A right bundle branch block tended to decrease the odds of CK-MB measuring positive (OR 0.658). A similar pattern of results was observed for troponin I (OR 3.608 for STE, 3.72 for STD, 1.538 for PQW). Troponin T showed an increased odds of measuring positive if any of STE, STD, left bundle branch block, or T-wave inversion were evident (OR 2.313, 2.816, 1.80, and 1.449, respectively). CONCLUSIONS: Initial ECG criteria can be used to predict short-term cardiac outcomes and positive cardiac markers. These findings can be important aids in the risk-stratification and aggressive treatment regimens of chest pain patients presenting to EDs. 相似文献
105.
106.
Jean-Pierre Chanoine MD PhD Sarah Hampl MD FAAP Craig Jensen MD Mark Boldrin MS Jonathan Hauptman MD 李呈亿 《美国医学会杂志》2006,25(1):34-43
背景:儿童和青少年超重和肥胖正迅速增加。在该人群,单纯行为疗法减肥及维持体重下降的效果有限,但是对药物治疗尚未进行广泛的研究。
目的:确定奥利州他(Orlistat)在青少年体重治疗方面的效果及其安个性。
设计、地点和病例:于美国和加拿大32个中心、539例肥胖青少年(12—16岁;体重指数[body mass index,BMI]在第95百分化之上≥2单位)进行的多ln0、54剧(2000年8月至2002年10月)随机双盲研究。
干预:给予奥利司他(n=357)或安慰剂(n=182)120mg,每口3次,持续1年;加适度低热卡饮食(脂肪占30%)、运动和行为治疗。
主要观察指标:BMI变化;二级指标包括腰围和髋用、体重下降、脂质测量以及机体对口服葡萄糖的血糖和胰岛素反心。
结果:至12周时,两组BMI均有下降;此后,奥利司他组体重维持稳定而安慰剂组则超过基线。研究结束时,奥利司他组BMI下降0.55。而安慰剂组则增加0.31(P=0.001)。与安慰剂组的15.7%相比,奥利司他组26.5%的病例BMI下降≥5%(P=0.005);BMI下降≥10%者分别为4.5%和13.3%(P=0.002)。在研究结束时,奥利司他组体重增加0.53kg,安慰剂组增加3.14kg(P〈0.001)。双能X线吸收测量娃示,这种差异可用脂肪体再的变化解释。奥利司他组腰围下降,安慰剂组腰围上升(-1.33cm比+0.12cm;P〈0.05)。奥利司他组发生轻至中度胃肠道不良事件者为9%-50%,安慰剂组为1%~13%。
结论:与安慰剂比较,奥利司他与饮食、运动和行为改善联合可显著改善肥胖青少年体重的治疗。在这个青少年人群,连续使用奥利司他1年并无重要安全问题,尽管奥利司他组胃肠道不良事件较为常见。 相似文献
107.
M N Levine J Hirsh M Gent A G Turpie J Leclerc P J Powers R M Jay J Neemeh 《Annals of internal medicine》1991,114(7):545-551
OBJECTIVE: To determine the relative efficacy and safety of low molecular weight (LMW) heparin (Enoxaparin) compared with standard calcium heparin for the prevention of postoperative deep vein thrombosis in patients undergoing elective hip surgery. DESIGN: A double-blind, randomized, controlled trial. PATIENTS: Six hundred sixty-five consecutive patients undergoing hip replacement at five participating hospitals. INTERVENTIONS: Patients received either fixed-dose LMW heparin, 30 mg subcutaneously twice daily, or fixed-dose standard calcium heparin, 7500 units subcutaneously twice daily; both regimens were started 12 to 24 hours after surgery and continued for 14 days or until discharge if sooner. MEASUREMENTS: All patients had postoperative I-125-fibrinogen leg scanning and impedance plethysmography. If results of one or both tests were positive, then venography was done. Otherwise, venography was done between day 10 and day 14, or sooner if the patient was ready for discharge. RESULTS: Evaluable venograms were obtained in 258 of the 333 patients randomly assigned to receive LMW heparin and in 263 of the 332 patients assigned to receive calcium heparin. For patients with evaluable venograms, thrombosis was detected in 50 patients (19.4%) who received LMW heparin compared with 61 patients (23.2%) who received standard heparin (difference, -3.8%; 95% CI, -11.1% to 3.6%) (P greater than 0.2). Proximal deep vein thrombosis was detected in 5.4% of the patients receiving LMW heparin and in 6.5% of the patients receiving standard heparin (difference, -1.1%; CI, - 5.2% to 3.3%) (P greater than 0.2). For the entire group of 665 patients, venous thrombosis occurred in 17.1% given LMW heparin and in 19.0% given standard heparin. Hemorrhagic complications occurred in 31 patients (9.3%) given standard heparin and in 17 patients (5.1%) given LMW heparin (difference, 4.2%; CI, 0.3% to 8.2%) (P = 0.035). The relative risk reduction was 45%. The rate of major bleeding in the standard heparin group was 5.7% compared with 3.3% in the LMW heparin group (difference, 2.4%; CI, -1.0% to 5.4%) (P = 0.13). The relative risk reduction was 42%. CONCLUSION: Low molecular weight heparin is significantly less hemorrhagic than standard unfractionated heparin; the difference in the rate of deep vein thrombosis, although not statistically significant (P greater than 0.2), favors the use of LMW heparin. 相似文献
108.
Ghassan M. Saed PhD ; Michael Kruger MS ; Michael P. Diamond MD 《Wound repair and regeneration》2004,12(5):557-564
109.
Regina P Walker Howard L Levine Martin L Hopp David Greene Kenny Pang 《Otolaryngology--head and neck surgery》2006,135(4):549-554
OBJECTIVE: To evaluate the short-term safety and efficacy of palatal implants in patients with mild and moderate obstructive sleep apnea (OSA). STUDY DESIGN AND SETTING: A prospective, non-randomized study conducted at 5 clinical sites. Three polyester implants were placed in the soft palate under local anesthesia during a single-stage office procedure. Polysomnography was conducted at baseline and 90 days post-procedure. Subjective quality of life data were collected. RESULTS: Fifty-three patients were evaluated; the apnea hypopnea index (AHI) decreased from 25.0 +/- 13.9 to 22.0 +/- 14.8 events/hour (P = 0.05). The Epworth Sleepiness Scale (ESS) decreased from 11.0 +/- 5.1 to 6.9 +/- 4.5 (P < 0.001), and the snore score decreased from 7.9 +/- 2.1 to 4.0 +/- 3.0 (P < 0.001). No serious complications occurred during the study. CONCLUSION: Palatal implants can be an effective initial low morbidity treatment option for patients diagnosed with mild to moderate OSA. 相似文献
110.
Rufus S. HoweCPT AN BSE BSN RN-C Claudia ChrlstmanCPT AN MS BA BSN RN-C 《Journal of the American Academy of Nurse Practitioners》1991,3(1):35-41
Noninsulin dependent diabetes (type II diabetes) is a chronic disease characterized by hyperglycemia. Clients can generally be controlled by diet and exercise or a combination of diet, exercise, and oral hypoglycemic agents. When this therapy is not effective in controlling the hyperglycemia, the health care provider must choose to initiate insulin therapy. Outpatient initiation of insulin is an alternative to hospitalization in the type II diabetic client. Clinical guidelines for the initiation of insulin on an outpatient basis and management of the diabetic client are presented. 相似文献