首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   22598篇
  免费   2466篇
  国内免费   775篇
耳鼻咽喉   170篇
儿科学   260篇
妇产科学   205篇
基础医学   946篇
口腔科学   562篇
临床医学   3762篇
内科学   1667篇
皮肤病学   162篇
神经病学   795篇
特种医学   573篇
外国民族医学   7篇
外科学   1345篇
综合类   3606篇
现状与发展   1篇
一般理论   1篇
预防医学   5564篇
眼科学   108篇
药学   3313篇
  77篇
中国医学   2129篇
肿瘤学   586篇
  2024年   92篇
  2023年   554篇
  2022年   816篇
  2021年   1100篇
  2020年   1177篇
  2019年   931篇
  2018年   879篇
  2017年   931篇
  2016年   999篇
  2015年   1006篇
  2014年   1785篇
  2013年   1951篇
  2012年   1647篇
  2011年   1641篇
  2010年   1247篇
  2009年   1174篇
  2008年   1084篇
  2007年   1046篇
  2006年   917篇
  2005年   725篇
  2004年   619篇
  2003年   531篇
  2002年   401篇
  2001年   364篇
  2000年   300篇
  1999年   315篇
  1998年   238篇
  1997年   180篇
  1996年   152篇
  1995年   132篇
  1994年   134篇
  1993年   98篇
  1992年   102篇
  1991年   81篇
  1990年   69篇
  1989年   58篇
  1988年   56篇
  1987年   36篇
  1986年   45篇
  1985年   49篇
  1984年   43篇
  1983年   19篇
  1982年   19篇
  1981年   18篇
  1980年   27篇
  1979年   8篇
  1978年   16篇
  1977年   11篇
  1975年   7篇
  1974年   3篇
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
71.
目的 探讨肱骨髁间骨折的手术方式并评价疗效。方法 1998年1月~2004年12月共手术治疗肱骨髁间骨折28例,进行随访分析。结果 28例中26例获随访,时间6个月~4年7个月,其中22例获2年以上随访。疗效评价参照casse‰。评分系统,优良率为65%。结论 骨折类型及手术方式直接影响预后。关节良好的复位和牢固的固定,以及术后早期积极的功能锻炼是得到良好疗效的保证。  相似文献   
72.
目的探讨改良《颈性眩晕症状与功能评估量表》在椎动脉型颈椎病(CSA)的中医临床中的应用可行性。方法151例CSA患者随机分为针灸推拿治疗组和单针灸对照组,治疗前后采用改良《颈性眩晕症状与功能评估量表》进行量化评估,并对该量表在本次中医临床中的效度及信度进行初步检验。结果治疗组治疗后症状与功能评分比治疗前有显著提高(p<0.01),治疗组改善指数明显高于对照组(p<0.05)。经检验,该量表也有可以接受的准则效度(r在0.8-0.9之间,p<0.01)和再测信度(r在0.6-0.9之间,p<0.01)。结论针灸推拿结合治疗CSA具有确切的临床疗效,能明显改善患者症状、颈椎功能和生活质量。改良《颈性眩晕症状与功能评估量表》在CSA中医临床中具有可信性、有效性。  相似文献   
73.
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   
74.
BACKGROUND: Diagnosis of atopic dermatitis (AD) depends on clinical features because no definitive diagnostic test exists. Criteria proposed by Hanifin and Rajka (Acta Derm Venereol (Stockh) 1980; Suppl 92: 44-47) were acceptable for hospital-based studies but were found not to be suitable for field studies. A UK working party formulated clinical diagnostic criteria that could be used in both hospital and epidemiological settings. Validation studies of the criteria showed widely variable results, probably due to different clinical settings and ethnicity. AIM AND OBJECTIVE: This study was undertaken to validate Hanifin and Rajka's criteria and to assess the comparative efficacy of their criteria and the UK working party's diagnostic criteria in the diagnosis of AD in a hospital setting in North India. SUBJECTS AND METHODS: This study serially included 101 patients with AD and 48 controls of paediatric age group. The study period was from July 2003 to December 2004. RESULTS: Hanifin and Rajka's criteria (sensitivity 96%, specificity 93.75%, positive predictive value 97% (PPV) and negative predictive value (NPV) 91.84%) had a statistical advantage over the UK working party's diagnostic criteria (sensitivity 86%, specificity 95.83%, PPV 97.75% and NPV 76.67%), with a P-value < 0.005.  相似文献   
75.
Background: Endoscopic mucosal resection (EMR) is widely accepted as a minimally invasive treatment for early gastric cancer (EGC) in Japan. However, the criteria for EMR must be strictly adhered to otherwise patients will miss the chance for additional therapy. We assess the important factor in expanding the indication of EMR. Methods: We investigated 1101 EGCs that had been resected by EMR at the National Cancer Center Hospital (NCCH), Tokyo, Japan, according to the indication recommended by Japanese Gastric Cancer Association (JGCA) and the expanded indication proposed by NCCH. Curability and local recurrence of the EMRs were assessed related to the applied indication and the number of resected specimens. Results: The recurrence rate of non‐evaluable resection was higher than that of evaluable resection (P < 0.0001). Eighty‐three lesions among 772 lesions in the JGCA group were non‐evaluable. Thirty‐seven leisons among 329 lesions in the NCCH group were non‐evaluable. There was no difference in the rate of non‐evaluable resection between JGCA and NCCH groups (P = 0.8329). However, the rate of curative resection was lower in the NCCH group than in the JGCA group (P = 0.0009). In piecemeal resection, there was no difference in the rate of non‐evaluable resection between JGCA and NCCH groups (P = 0.0527). In one‐piece resection, the rate of non‐evaluable resection was lower in the NCCH group than the JGCA group (P = 0.0137). Conclusion: Based on our series of cases, we propose one‐piece resection as a gold standard for EMR because it enables accurate histological evaluation, even in the EMR, according to the expanded indication.  相似文献   
76.
Aim:  To present an evidence-based framework to improve the quality of occupational therapy expert opinions on work capacity for litigation, compensation and insurance purposes.
Methods:  Grounded theory methodology was used to collect and analyse data from a sample of 31 participants, comprising 19 occupational therapists, 6 medical specialists and 6 lawyers. A focused semistructured interview was completed with each participant. In addition, 20 participants verified the key findings.
Results:  The framework is contextualised within a medicolegal system requiring increasing expertise. The framework consists of (i) broad professional development strategies and principles, and (ii) specific strategies and principles for improving opinions through reporting and assessment practices.
Conclusions:  The synthesis of the participants' recommendations provides systematic guidelines for improving occupational therapy expert opinion on work capacity.  相似文献   
77.
某地13所医院1997-2001年门诊费用的基本分析与评价   总被引:7,自引:0,他引:7  
采用回顾性调查分析方法,对某地13所医院1997-2001年门诊费用变动情况进行分析。统计学处理结果提示样本医院5年来门诊费用平均发展速度和平均增长速度加快明显。作者对此提出借鉴国外教训、避免浪费的建议,以应对医疗费飞涨给全局工作带来的各种冲击。  相似文献   
78.
目的:通过对HIV抗体快速检测试剂的临床评估,为HIV检测试剂的临床应用提供参考.方法:对快速试剂的使用性能进行比较,并采用美国输血协会(AABB)血清盘、临床样品血清盘、特性血清盘(阳性样品盘)、稀释系列血清盘评估快速试剂的敏感性和特异性.结果:三种快速试剂在检测AABB血清盘时,敏感性分别是86.4%、86.4%、100%,特异性皆为100%;三种快速试剂在检测临床样品血清盘时,敏感性分别是88.6%、91.4%、97.1%,特异性皆为100%.快速试剂具有很高的阳性预期值,对于低危人群(感染率很低人群)也具有很高的阴性预期值.快速试剂检测弱阳性的样品(酶联试剂s/co比值小于6~8的样品)存在漏检.快速试剂与ELISA参考试剂在分析灵敏度方面相差3个以上倍比稀释度.结论:快速试剂具有较好的使用特性,非常适用于样本量较少的实验室及对低危人群的HIV筛查,在对高危人群筛查时,可能有弱阳性样品漏检,同时快速试剂在分析灵敏度方面有待提高.  相似文献   
79.
Systemic lupus erythematosus (SLE) is the archetypical immunologic disease. Approximately 20% of patients present in the first two decades of life. This article highlights some of the differences between pediatric and adult onset lupus.Children are defined as different from adults on the basis of age. Lupus presents with different gender ratios based on hormonal or pubertal status with more significant skewing toward female patients in the childbearing years. Female patients in the childbearing years appear to have a higher relative risk for mortality. Despite this, children have greater disease severity at onset based on the number of patients who present with significant organ inflammation, the amount of corticosteroids required and the abnormalities in lupus serologies including autoantibodies and low complements. Children present frequently with congenital and acquired complement defects. Children have an increased risk of infections that can be confused with lupus. They have a higher risk of serious pneumococcal infection and may have less protection from vaccinations received at the time of disease onset.The clinical immunology laboratory is critical in the diagnosis and treatment of pediatric SLE. The rapid analysis and transfer of laboratory results can be life saving for the child with suspected new onset lupus. The laboratory is also helpful in determining disease activity through analysis of immunologic trends over time in pediatric lupus patients. This is especially important in the noncompliant adolescent patient who has a correlation between disease activity and lupus serologic tests. Finally, the clinical immunology laboratory is an important tool for better understanding of the immunologic phenomena associated with lupus and of disease pathophysiology.  相似文献   
80.
艺术嗓音歌声客观评价初探   总被引:1,自引:0,他引:1  
目的探讨客观评价艺术嗓音歌声的方法。方法对48名声乐专业青年大学生录制专业训练歌声信号,提取歌声平均能量、频率误差、音域误差作为评价参数,使用神经网络方法和多元线性回归方法客观评价歌声质量,并与资深专业教师的主观评价进行比较。结果客观评价歌声质量的方法中,神经网络方法误差在4%之内,而线性回归方法误差在6%之内,前者较优。结论神经网络方法利用评价参数能正确客观评价歌声质量,有助于科学地指导选拔和训练艺术嗓音人才。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号