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   5056篇
  免费   395篇
  国内免费   131篇
耳鼻咽喉   98篇
儿科学   104篇
妇产科学   56篇
基础医学   665篇
口腔科学   149篇
临床医学   392篇
内科学   756篇
皮肤病学   50篇
神经病学   669篇
特种医学   132篇
外科学   405篇
综合类   438篇
预防医学   714篇
眼科学   87篇
药学   562篇
  1篇
中国医学   162篇
肿瘤学   142篇
  2024年   10篇
  2023年   122篇
  2022年   207篇
  2021年   270篇
  2020年   234篇
  2019年   266篇
  2018年   228篇
  2017年   209篇
  2016年   159篇
  2015年   141篇
  2014年   313篇
  2013年   376篇
  2012年   216篇
  2011年   269篇
  2010年   200篇
  2009年   248篇
  2008年   222篇
  2007年   218篇
  2006年   180篇
  2005年   155篇
  2004年   138篇
  2003年   123篇
  2002年   104篇
  2001年   85篇
  2000年   71篇
  1999年   69篇
  1998年   43篇
  1997年   48篇
  1996年   57篇
  1995年   49篇
  1994年   41篇
  1993年   42篇
  1992年   53篇
  1991年   43篇
  1990年   39篇
  1989年   42篇
  1988年   33篇
  1987年   22篇
  1986年   33篇
  1985年   33篇
  1984年   27篇
  1983年   18篇
  1982年   21篇
  1981年   28篇
  1980年   13篇
  1979年   15篇
  1978年   6篇
  1977年   8篇
  1976年   6篇
  1974年   12篇
排序方式: 共有5582条查询结果,搜索用时 31 毫秒
81.
赵慧  杨士娴 《职业与健康》2006,22(2):101-102
目的探讨铅作业工人尿铅有无性别上差异。方法选择接触铅作业1 a以上,并且平均年龄及铅作业工龄段人数构成比均相近的不同性别的两组工人(女工组1 133名,男工组342名)作为研究对象,测定其尿铅,对测定结果进行统计学分析。结果女工组同工龄尿铅异常发生率除25岁~组外,其他均明显高于男工组,女工组尿铅异常总发生率为29.7%,与男工相比(8.2%),差异有非常显著性,P<0.01。结论铅对作业工人尿铅的影响有性别差异,女性高于男性。是否与女性的解剖生理特点及对毒物的敏感性高有关,有待于继续研究。  相似文献   
82.
This study was undertaken to examine whether males develop schizophrenia at a younger age than females, and whether temporal socioeconomic change affects the age at onset of schizophrenia. The subjects were 848 ICD-9 schizophrenics who were admitted to Nihon University Hospital, Tokyo, Japan, during the period of 1955-64 (n = 468 (214 males and 254 females), group A) or during the period of 1982-91 (n = 380 (220 males and 160 females). group B). Schizophrenic males showed an earlier age at onset than schizophrenic females. However, the mean age at onset of schizophrenia did not differ significantly between group A and group B. These results indicate that the gender difference in age at onset of schizophrenia has not been influenced by temporal socioeconomic change.  相似文献   
83.
从“察同”、“察异”的东西方科学认识事物的不同取向入手,对“肝肾同源”理论进行较为全面的评价。“肝肾同源”理论追求对事物的共性认识,对指导“肝肾同治”具有积极的意义,但其“察异”的不足也带来忽视肝、肾个性的弊端,尤其是“肝”之个性的忽视。  相似文献   
84.
中药与日本汉方药原植物的差异比较及原因分析   总被引:1,自引:1,他引:1  
依据 2000年版《中国药典》和第十四改《正日本药局方》收载植物类生药品种 ,列表比较了中药与日本汉方药原植物的差异 ,并对产生差异的现象和原因进行了分析和探讨。  相似文献   
85.
AIM: To investigate the Chinese version of the Low Vision Quality of Life Questionnaire (CLVQOL) as an instrument for obtaining clinically important changes after cataract surgery. METHODS: Patients underwent cataract surgery in Shanghai General Hospital, Shanghai Jiao Tong University, who fit the inclusion criteria were recruited. Two CLVQOLs were administered, including a preoperative CLVQOL and a CLVQOL at the end of the 3mo follow-up period, and were completed using face-to-face interviews or phone interviews conducted by trained investigators. The minimal clinically important difference (MCID) was calculated using an anchor-based method and a distribution method. In addition, the responsiveness of the questionnaire was measured. RESULTS: A total of 155 residents were enrolled. The average visual acuity (VA) preoperatively was 0.08 (SD=0.05), and it increased to 0.47 (SD=0.28) at the end of follow-up. Statistically significant positive changes in the CLVQOL scores indicated significant improvement of vision related quality of life after cataract surgery. With the larger value between the two results as the final value, the MCID values of the CLVQOL (scores of the four scales as well as the total score) were 8.94, 2.61, 4.34, 3.10 and 17.63, respectively. The CLVQOL has both good internal and external responsiveness. CONCLUSION: CLVQOL scores are appropriate instruments for obtaining clinically important changes after cataract surgery. This study is an effective exploration for establishing cataract surgery efficacy standards, which helps clinical and scientific research workers in ophthalmology to gain a more in-depth understanding when using CLVQOL.  相似文献   
86.
87.
88.
Due to a scarcity of available skeletal material, anthropologists and other practitioners face difficulties with either the creation or validation of techniques used to estimate a biological profile in subadults. To address this problem, radiographic images of living individuals are often used in lieu of dry skeletal elements. However, radiographic images suffer from distortion. Some problems with metric analyses when using radiographic images may be addressed with the Lodox Statscan, an X‐ray machine that claims to produce minimal distortion along the scan‐axis due to a linear slot‐scanning design. The purpose of this research was to measure the distortion of skeletal elements in radiographic images generated from a Lodox Statscan. Skeletal elements subject to multiple imaging variables that affect distortion were radiographed, measured, and then compared to the dry bone measurements through multiple approaches. An 85% percent agreement within a ±1 mm range and a 97% agreement within a ±2 mm range was obtained. Percent difference results demonstrate that slot‐axis measurements incurred more distortion than scan‐axis measurements (11.8% and 2.7%, respectively). Inclusion of foam results in 4.5% more error than when foam is not included in the image. Angled scan‐axis measurements also incurred more distortion than either nonangled slot‐ and scan‐axis measurements. A Bland‐Altmanplot reveals an overall agreement between the radiographic and dry bonemeasurements, with most measurements falling within the upper and lower limits. Similar measurement error is found in Statscan radiographic and dry bone measurements; therefore, the Statscan offers a radiographic venue to collect metric data. Clin. Anat. 26:780–786, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   
89.
Methods for measuring masking level differences (MLDs) at 500 Hz and for spondees were used with 290 subjects: 50 persons with normal hearing and 240 patients with various diseases. Of particular interest was whether techniques currently in clinical use could be used with ease, dispatch, and profit in determining MLD size. The methods selected, which were variations of Békésy audiometry and speech reception threshold procedures, proved clinically feasible

Results revealed differences in behavior from one group of subjects to another. Although MLDs were not affected by cortical lesions, they were very often abnormally small for patients with eighth-nerve tumor, Menière's disease, or multiple sclerosis

The high incidence of abnormally small MLDs in populations with normal sensitivity to pure tones and speech but with evidence of subcortical central lesions, such as patients with multiple sclerosis, suggests that the MLD tasks can be of diagnostic value in detecting retrocochlear lesions. However, in persons with hearing loss or significant interaural differences in threshold sensitivity, or both, the MLD tests are not always reliable in differentiating cochlear from retrocochlear disease  相似文献   
90.
ObjectiveTo evaluate the effectiveness and adverse events of autologous platelet-rich plasma (PRP) in individuals with lower-extremity diabetic ulcers, lower-extremity venous ulcers, and pressure ulcers.Patients and MethodsWe searched multiple databases from database inception to June 11, 2020, for randomized controlled trials and observational studies that compared PRP to any other wound care without PRP in adults with lower-extremity diabetic ulcers, lower-extremity venous ulcers, and pressure ulcers.ResultsWe included 20 randomized controlled trials and five observational studies. Compared with management without PRP, PRP therapy significantly increased complete wound closure in lower-extremity diabetic ulcers (relative risk, 1.20; 95% CI, 1.09 to 1.32, moderate strength of evidence [SOE]), shortened time to complete wound closure, and reduced wound area and depth (low SOE). No significant changes were found in terms of wound infection, amputation, wound recurrence, or hospitalization. In patients with lower-extremity venous ulcers or pressure ulcers, the SOE was insufficient to estimate an effect on critical outcomes, such as complete wound closure or time to complete wound closure. There was no statistically significant difference in adverse events.ConclusionAutologous PRP may increase complete wound closure, shorten healing time, and reduce wound size in individuals with lower-extremity diabetic ulcers. The evidence is insufficient to estimate an effect on wound healing in individuals with lower-extremity venous ulcers or pressure ulcers.Trial RegistrationPROSPERO Identifier: CRD42020172817  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