全文获取类型
收费全文 | 1454688篇 |
免费 | 123055篇 |
国内免费 | 3961篇 |
专业分类
耳鼻咽喉 | 22173篇 |
儿科学 | 43393篇 |
妇产科学 | 41605篇 |
基础医学 | 194177篇 |
口腔科学 | 45000篇 |
临床医学 | 141186篇 |
内科学 | 289308篇 |
皮肤病学 | 33908篇 |
神经病学 | 120488篇 |
特种医学 | 57610篇 |
外国民族医学 | 435篇 |
外科学 | 227163篇 |
综合类 | 31398篇 |
现状与发展 | 46篇 |
一般理论 | 467篇 |
预防医学 | 107639篇 |
眼科学 | 33961篇 |
药学 | 103039篇 |
4篇 | |
中国医学 | 3038篇 |
肿瘤学 | 85666篇 |
出版年
2018年 | 18902篇 |
2017年 | 16954篇 |
2016年 | 18548篇 |
2015年 | 19979篇 |
2014年 | 27303篇 |
2013年 | 37811篇 |
2012年 | 38723篇 |
2011年 | 40383篇 |
2010年 | 28221篇 |
2009年 | 29658篇 |
2008年 | 38733篇 |
2007年 | 40904篇 |
2006年 | 42415篇 |
2005年 | 39980篇 |
2004年 | 38250篇 |
2003年 | 36818篇 |
2002年 | 36165篇 |
2001年 | 65566篇 |
2000年 | 66534篇 |
1999年 | 57181篇 |
1998年 | 16918篇 |
1997年 | 15473篇 |
1996年 | 14887篇 |
1995年 | 13945篇 |
1994年 | 12619篇 |
1992年 | 43535篇 |
1991年 | 41965篇 |
1990年 | 41115篇 |
1989年 | 40118篇 |
1988年 | 37502篇 |
1987年 | 36811篇 |
1986年 | 35279篇 |
1985年 | 33444篇 |
1984年 | 25133篇 |
1983年 | 21383篇 |
1982年 | 12937篇 |
1981年 | 11800篇 |
1979年 | 24026篇 |
1978年 | 17203篇 |
1977年 | 14978篇 |
1976年 | 13487篇 |
1975年 | 15351篇 |
1974年 | 18171篇 |
1973年 | 17623篇 |
1972年 | 16905篇 |
1971年 | 15770篇 |
1970年 | 14983篇 |
1969年 | 14376篇 |
1968年 | 13483篇 |
1967年 | 12028篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
Clinical decisions are often made with incomplete information, yet patient care decisions are made every day. Patients vary clinically, uncertainty exists in diagnostic and prognostic information, and many preventive and treatment alternatives have not been formally assessed for their effectiveness. Because scientific information will never answer all clinical questions, clinical decisions are partially based on probabilistic information.
This paper describes how to apply clinical decision making to diagnosing and managing dental caries and periodontal diseases. By using explicit information to quantify probabilities and outcomes, clinical decision making analyzes decisions made under uncertain conditions and the uncertain impact of clinical information.
Clinical decision making incorporates concepts for preventing, diagnosing and treating dental caries and periodontal diseases: risk assessment, evidence-based dentistry, and multiple oral health outcomes. This information can serve as a tool for clinicians to augment clinical judgment and expertise. 相似文献
This paper describes how to apply clinical decision making to diagnosing and managing dental caries and periodontal diseases. By using explicit information to quantify probabilities and outcomes, clinical decision making analyzes decisions made under uncertain conditions and the uncertain impact of clinical information.
Clinical decision making incorporates concepts for preventing, diagnosing and treating dental caries and periodontal diseases: risk assessment, evidence-based dentistry, and multiple oral health outcomes. This information can serve as a tool for clinicians to augment clinical judgment and expertise. 相似文献
52.
Tony R Cucuzzella Elva G Delport Nancy Kim Julie Marley Christine Pruitt Anton G Delport 《The spine journal》2006,6(4):364-369
BACKGROUND CONTEXT: Substantial variation exists regarding the use of sedation before interventional spine techniques. Patient preference should play an important role in decision making regarding the need for sedation. However, little is known about patients' anxiety levels before spinal injections and their perceptions about the necessity of sedation. PURPOSE: To determine patient perception for need for sedation before epidural steroid injections and zygapophyseal joint injections. STUDY DESIGN/SETTING: Survey of consecutive spinal injection patients in an outpatient spine center. PATIENT SAMPLE: 500 consecutive lumbar, thoracic, and cervical patients receiving spinal injections. OUTCOME MEASURES: A 12-item questionnaire assessing patients' perceived anxiety before to a spinal injection. METHODS: Subjects were given the questionnaire after their spinal injection. Percentages requesting sedation for a first and potential second procedure were assessed. Additionally, anxiety level and pain rating, location of injection, age, sex, and other medication use were analyzed to determine the effect on the request for sedation. RESULTS: 17% of patients questioned requested sedation before an injection, and 28% would request sedation if they were to have a second injection. CONCLUSIONS: Routine sedation before diagnostic and therapeutic injections is not necessary as the majority of patients would not request sedation before the procedure when given the option. However, in some patients sedation is indicated, and all patients would benefit from educational material on sedation before the injection. 相似文献
53.
Severe adverse effects during the use of ovulation inhibitors occur mostly in women who have an elevated risk for the development of certain diseases owing to hereditary or acquired factors. By means of a careful personal or family history analysis as well as specific laboratory examinations, an existing predisposition may frequently be diagnosed and the individual risk associated with the use of oral contraceptive inhibitors may be estimated. The present contribution describes the potential effects of treatment with ovulation inhibitors on women with thrombophilia, cardiovascular disease, diabetes mellitus, dyslipidemia, overweight or underweight, tumors, psychiatric and neurological diseases and autoimmune disease. The hormonal methods and non-hormonal alternatives available for contraception are elucidated according to existing lesions and risk factors and the advantages and disadvantages are discussed. 相似文献
54.
M Bernasconi P N Chhajed F Gambazzi L Bubendorf H Rasch S Kneifel M Tamm 《The European respiratory journal》2006,27(5):889-894
There are no data available combining transbronchial needle aspiration (TBNA) of mediastinal lymph nodes and positron emission tomography (PET) in the staging of nonsmall cell lung cancer (NSCLC). The aim of the current study was to determine if these two methods can enhance the negative predictive value of the individual modality alone, for a specific lymph node station, and if this integrated approach can reduce the number of mediastinoscopies. A total of 113 patients with enlarged mediastinal lymph nodes (> or = 1 cm), who underwent both TBNA and PET scanning, were included. In 51 patients, histopathology, confirmed by surgical lymph node dissection, was compared with PET results and TBNA. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy to detect malignant lymphadenopathy was 68 (13/19), 89 (119/134), 46 (13/28), 95 (119/125) and 86% (132/152) for PET, respectively; 54% (6/11), 100 (53/53), 100 (6/6), 91 (53/58) and 92% (59/64), respectively for TBNA; and 100 (11/11), 94 (50/53), 79 (11/14), 100 (50/50) and 95 (61/64) for combined TBNA and PET, respectively. Combination of transbronchial needle aspiration and positron emission tomography has the potential to allow adequate mediastinal staging of nonsmall cell lung cancer with enlarged lymph nodes in most patients without the need for mediastinoscopy. 相似文献
55.
56.
57.
58.
59.
A new semi-empirical formula for the evaluation of (n,(3)He) reaction cross-sections at the energy of 14.6 and 20 MeV is presented. Formula was derived using the analytical expression for the evaluation of the (3)He spectrum within the frame of pre-equilibrium exciton model. The systematics obtained is compared with the empirical formula for the (n,(3)He) reaction cross-section. 相似文献
60.
M Engelhardt P Bast N Jeblink W Lauer A Popovic H Eufinger M Scholz A Christmann A Harders K Radermacher K Schmieder 《Minimally invasive neurosurgery》2006,49(2):98-103
This study was performed to evaluate the surgical strategy in patients with calvarial tumours, in order to design and modify a robot-assisted trepanation system. A total of 75 patients underwent craniectomy for the treatment of calvarial tumours during the 10-year period from 1993 to 2002. The patients' complaints, the size, location and histology of the tumour, and the various cranioplasty techniques used were analysed retrospectively. In a second procedure several craniectomies at typical locations according to the study's results were performed in a laboratory setting using a hexapod robotic tool, constructed at the Helmholtz-Institute, RWTH Aachen University, and plastic model heads. The workflow was documented and the reproducibility and the accuracy of the procedure were registered. A total of 83 surgical procedures were performed on 75 patients. The majority (87 %) of lesions treated surgically were located in the frontal, temporal and anterior parts of the parietal region. Histological examination revealed benign lesions in 66 % of the patients and dural involvement in 46 %. According to these results craniectomies were performed using the robotic system. Mean positioning accuracy of the robotic system while milling was 0.24 mm, with a standard deviation of 0.04 mm, and maximum error under 1 mm. Craniectomies leaving a 1-mm layer of the tabula interna intact to ensure a healthy dura were performed in several regions successfully. The majority of calvarial tumours, requiring surgical treatment in our patients, were located in cosmetically relevant areas in which drilling can be carried out with the robotic trepanation system. Consequently, the surgical approach had to be planned carefully in order to achieve a good cosmetic outcome. 相似文献