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   87567篇
  免费   10278篇
  国内免费   4836篇
耳鼻咽喉   925篇
儿科学   1553篇
妇产科学   747篇
基础医学   5089篇
口腔科学   1890篇
临床医学   11537篇
内科学   8934篇
皮肤病学   1187篇
神经病学   2422篇
特种医学   3743篇
外科学   7919篇
综合类   21632篇
现状与发展   13篇
一般理论   4篇
预防医学   11718篇
眼科学   1039篇
药学   9263篇
  119篇
中国医学   8445篇
肿瘤学   4502篇
  2024年   487篇
  2023年   1431篇
  2022年   2791篇
  2021年   3628篇
  2020年   3279篇
  2019年   1766篇
  2018年   2252篇
  2017年   2818篇
  2016年   2300篇
  2015年   3861篇
  2014年   4790篇
  2013年   6216篇
  2012年   7643篇
  2011年   7966篇
  2010年   7378篇
  2009年   6715篇
  2008年   6405篇
  2007年   6128篇
  2006年   5411篇
  2005年   4215篇
  2004年   2979篇
  2003年   2423篇
  2002年   1962篇
  2001年   1828篇
  2000年   1247篇
  1999年   625篇
  1998年   410篇
  1997年   426篇
  1996年   420篇
  1995年   335篇
  1994年   265篇
  1993年   258篇
  1992年   183篇
  1991年   146篇
  1990年   144篇
  1989年   171篇
  1988年   144篇
  1987年   129篇
  1986年   134篇
  1985年   114篇
  1984年   100篇
  1983年   97篇
  1982年   80篇
  1981年   78篇
  1980年   49篇
  1979年   36篇
  1978年   43篇
  1977年   45篇
  1976年   35篇
  1972年   23篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The elderly (age >65 years) are more vulnerable to side-effects induced by non-steroidal anti-inflammatory drugs (NSAIDs). We therefore performed a double-blind comparative study of ketoprofen SR and sulindac in patients with active rheumatoid arthritis, 65 years of age or older. Sulindac was chosen because of its possible renal sparing effects, and ketoprofen SR because of its short half life and sustained release delivery system. Eighty patients were entered. More patients withdrew from the study due to side-effects in the sulindac group; both treatment groups had a high incidence of side-effects during this study and during previous exposure to other NSAIDs, demonstrating that the elderly are susceptible to side-effects from NSAIDs.  相似文献   
82.
83.
构建玻片蛋白质芯片的实验研究   总被引:2,自引:0,他引:2  
目的:探讨玻片蛋白质芯片的构建方法及其中间操作条件的选择与优化。方法:利用生物芯片点样仪将超微量蛋白质点到经特殊处理的玻璃片表面,然后选用不同的化学试剂对玻片背景进行封闭;再用荧光素标记的蛋白质与点样蛋白杂交;最后用生物芯片分析仪扫描成像并进行分析,比较不同条件下芯片的显示效果。结果:蛋白质样品与片基稳定结合,并保持原活性状态;封闭试剂选用酪蛋白或明胶效果较佳;点样探针与其特异蛋白质抗体可稳定结合,结合效果与点样蛋白浓度在一定范围内呈正相关;在1.6 cm×1.6 cm的玻璃片面积上,构建了36×36=1269点的蛋白质芯片。结论:本实验条件下,蛋白质抗原或抗体可以稳定地固定于经过处理的玻璃片表面.制成免疫型蛋白芯片,并可通过随后的抗原抗体反应与荧光素标记的相应抗体或抗原结合,用生物芯片分析仪可对其荧光信号进行检测分析。  相似文献   
84.
通过正硅酸甲酯(TMOS)的水解缩合反应制备了聚甲氧基硅氧烷(PMOS),其分子式可表示为:[SiOa(OH)b(OCH3)c]n。用丙烯酸-2-羟乙酯(HEA)进行酯交换后,制的功能化产物聚丙烯酰氧基甲基硅氧:烷(PAMOS),其分子式可表示为:[SiOd(OH)c(OCH3)f(OCH2CH2OCOCH=CH2)g]k。通过二氧化硅分析、红外光谱(FTIR)、凝胶渗透色谱(GPC)等方法确定了分子式中a、b、c、n及d、e、f、g、k的值,是一种比较方便、快捷且准确的方法。  相似文献   
85.
综合医院心理咨询门诊儿童咨客分析   总被引:6,自引:2,他引:4  
目的;了解综合医院心理咨询门诊儿童咨客的特点。方法:总结中山大学附属三院心理咨询门诊近3年儿童咨客的资料。结果:咨客男女比例为1.96:1,咨客人数随着年龄的增长而增加,女童中13-16岁的比例男童大,5-8岁和9-12岁的比例较男童小。广州市内外的咨客比例为1.38:1,不同年龄儿童咨客的居住地构成是有差异的。最常见的病种是精神分裂症,神经症、精神发育迟滞,儿童多动症,单纯咨询和品行障碍,不同年龄,不同性别的儿童咨客的疾病构成是有差异的。结论:综合医院心理咨询门诊与儿童心理咨询门诊的儿童咨客是有差异的。  相似文献   
86.
Congenital analgesia is a rare genetic disorder. We report here that a 12-year-old boy was able to recover from congenital insensitivity to pain. Neurological examinations revealed that there was a 'stocking' distribution of pain decrement on the lower extremities under the patient's knee joints. Magnetic Resonance Imaging (MRI) of his brain showed gyrus thinning with sulcus widening at both sides of the parietal lobe. Southern blot hybridization probed with cDNAs of various opioid receptors did not detect any significant abnormality. Our results suggest that this rare case may not be genetically determined.  相似文献   
87.
Urban and Rural Differences in Health Insurance and Access to Care   总被引:3,自引:0,他引:3  
This study considers differences in access to health care and insurance characteristics between residents of urban and rural areas. Data were collected from a telephone survey of 10,310 randomly selected households in Minnesota. Sub-samples of 400 group-insured, individually insured, intermittently insured, and uninsured people, were asked about access to health care. Those with group or individual insurance were also asked about the costs and characteristics of their insurance policies.
Rural areas had a higher proportion of uninsured and individually insured respondents than urban areas. Among those who purchased insurance through an employer, rural residents had fewer covered benefits than urban residents (5.1 vs 5.7, P < 0.01) and were more likely to have a deductible (80% versus 40%, P < 0.01). In spite of this, rural uninsured residents were more likely to have a regular source of care than urban residents (69% versus 51%, P < 0.01), and were less likely to have delayed care when they thought it was necessary (21% versus 32%, P<0.01). These differences were confirmed by multivariate analysis.
Rural residents with group insurance have higher out-of-pocket costs and fewer benefits. Uninsured rural residents may have better access to health care than their urban counterparts. Attempts to expand access to health care need to consider how the current structure of employment-based insurance creates inequities for individuals in rural areas as well as the burdens this structure may place on rural providers.  相似文献   
88.
Perceptions of family cohesion and hierarchy structures were assessed by theFamily System Test (FAST), a clinically-derived figure placement technique. Parents (N=140) and their preadolescent offspring (N=70) completed typical and conflict representations in individual as well as group settings. Typical representations were characterized by balanced family structures (i.e. cohesive and moderately hierarchical) and those displaying conflict situations showed predominantly unbalanced patterns. FAST portrayals were related to respondent (mother vs. father vs. child). Fathers represented typical family relations as balanced more often than mothers. Regarding conflict representations, children were more likely than fathers to portray the family as unbalanced. However, analyses of representations of the same family (i.e. intra-family comparisons) indicated that all respondents differed in their perceptions and, that fathers' typical portrayals showed most often the same structure as those done by the family members as a group.  相似文献   
89.
随着磁共振功能成像技术的发展,尤其是弥散张量成像(d iffusion tensor,DTI)及血氧依赖水平磁共振成像(b lood ox-ygenation level dependent,BOLD)技术的日臻完善,在活体状态下显示活动的皮质区并无创跟踪脑内白质纤维,反映解剖连通性已成为可能。本文就功能磁共振BOLD、DTI联  相似文献   
90.
绒山羊是青海海西州经济社会发展的基础性产业,本文从海西州资源、社会、经济等方面出发,结合绒山羊生物学特点,对当地绒山羊业发展提出一些问题和建议。  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