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1.
Cadmium (Cd) is an environmental endocrine-disrupting pollutant which mainly occurs in pulsed manner in natural waters, while traditional toxicology experiments have less examined the effects of pulsed exposure. Here, we studied the effects of short-term (7 days) continuous and pulse exposure to 100 μg/L Cd on gut morphology and microbiota of frogs (Pelophylax nigromaculatus) during pre-hibernation. Compared to continuous exposure, Cd pulse exposure significantly increased individual mortality and decreased the villi height and the ratio of villi height to crypt depth of the gut. Cd continuous and pulse exposure both changed the community structure and relative abundance of intestinal microbiota. Compared to continuous exposure, Cd pulse exposure significantly decreased the relative abundance of beneficial bacteria (e.g., Cetobacterium and Aeromonas genus), and significantly increased the relative abundance of harmful bacteria (e.g., Parabacteroides, Odoribacter, and Acinetobacter genus). This study shows that the gut histology and microbiota of amphibians during pre-hibernation are more susceptible to Cd pulse exposure than continuous exposure.  相似文献   
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目的 调查核实平潭综合实验区甲状腺癌是否高发,并分析其发病特征。方法 选择福建省肿瘤发病报告系统中发病日期为2013—2015年的平潭户籍甲状腺癌病例;通过查阅医院病历资料核实基本信息和诊断信息,随访排除非户籍病例。计算粗发病率、标化率、累积率,分析甲状腺癌在不同性别、年龄发病情况,及不同病理类型和不同大小肿瘤的构成。中国人口标化率根据2000年中国标准人口构成计算,世界人口标化率按Segi′s世界人口构成计算。结果 2013—2015年平潭综合实验区甲状腺癌新发病例共881例;其中男性205例,女性676例。甲状腺癌粗发病率为69.30/10万,中标率为65.27/10万;男性粗发病率及中标率分别为31.78/10万和29.87/10万;女性粗发病率及中标率分别为107.95/10万和101.19/10万;女性发病是男性的3.18倍。男、女性中位发病年龄分别为46岁和47岁。男性在40-年龄组达到发病高峰,女性在45-年龄组和55-年龄组形成两个发病高峰。乳头状癌、滤泡状癌、髓样癌及其他病理类型占比分别为96.52%、1.80%、0.60%和1.08%。肿瘤最大径≤10 mm的微小癌占77.29%。结论 平潭综合实验区甲状腺癌发病高于同期福建省及全国平均水平,以乳头状癌为主,微小癌占比较高。  相似文献   
4.
随着国内高等医学教育管理体制改革的日益深化和素质教育的全面推进,医学院校的教学实验室建设从以往单一学科设置、传统的基础医学教学实验室逐步演变为按功能分类、按学科群布局的基础医学实验教学中心。在陆军军医大学基础医学实验教学中心建设过程中,从构建“大中心”、创建实验教学课程新体系、探索创新实践教育新模式、创建优秀实验教师队伍等方面进行了实践探索,相关工作为今后实验教学中心的建设提供了实践参考。  相似文献   
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随着"互联网+高等教育"打破传统教育的时空界限和学校围墙,慕课平台的大力发展,慕课建设成为如今教学模式的新改革,中国医科大学附属第一医院实验诊断学教研室承担《实验诊断学》的慕课课程建设工作,并首次将主题创意设计的理念应用于医学教育的慕课建设中。课程内容涵盖目前5大专业,9章,19节,82个热门检测项目。本文从主题创意设计的课程设计理念、构建课程框架、组建主题创意团队等多方面探讨实验诊断学慕课课程建设的过程,并通过微信公众号分别对在校学生和社会人士进行关于主题创意设计理念的慕课设计的教学效果评价及满意度调查。调查结果显示在校学生及在职人员实验组的随堂小考成绩、满意度调查得分均高于对照组,差异具有统计学意义(t=4.266、4.689、4.198、3.869,P <0.001)。主题创意设计理念的慕课设计,有助提高学生对实验诊断课程的兴趣,提高慕课教学的教学质量,且在医学继续教育的领域,也可对相关专业的在职人员起到继续教育的作用。  相似文献   
6.
Since 2001, Pyrenean chamois (Rupicapra pyrenaica pyrenaica) populations have been affected by border disease virus (BDV) causing mortalities of more than 80% in some areas. Field studies carried out in France, Andorra, and Spain have shown different epidemiological scenarios in chamois populations. This study was designed to confirm the presence of BDV strains of a high and low virulence in free‐ranging chamois populations from Pyrenees and to understand the implications of these findings to the diverse epidemiological scenarios. An experimental infection of Pyrenean chamois with a high‐virulence (Cadí‐6) and low‐virulence (Freser‐5) BDV strains was performed. Pregnant and non‐pregnant animals with and without antibodies against BDV were included in each group. Cadí‐6 BDV strain was confirmed to be of high virulence for seronegative adults and their foetuses. The antibody negative chamois infected with Freser‐5 BDV strain did not show symptoms, presented less viral distribution and RNA load in tissues than Cadí‐6 group, and cleared the virus from the serum. However, foetuses died before the end of the experiment and RNA virus was detected in sera and tissues although with lower RNA load than the Cadí‐6 group. Chamois from both groups presented lesions in brain but the ones infected with the low‐virulence Freser‐5 BDV strain were mild and most likely transient. In both groups, seropositive pregnant females and all but one of their foetuses did not present viraemia or viral RNA in tissues. The existence of a low‐virulence strain has been confirmed experimentally and related to chamois population infection dynamics in the area where it was isolated. Such strain may persist in the chamois population through PI animals and may induce cross‐protection in chamois against high‐virulence strains. This study demonstrates that viral strain diversity is a significant factor in the heterogeneity of epidemiological scenarios in Pyrenean chamois populations.  相似文献   
7.
Introduction: Both the neuropsychological study of patients with category-specific semantic disorders (CSSD) and the experimental research on categorical processing in healthy subjects (HSs) have shown that men are mainly impaired with fruits and vegetables and women with animals and artifacts. Since this difference is more striking in patients with CSSD than in HSs, we hypothesized that the lack of power of some investigations conducted with HSs and the different methods used in studies conducted with HSs and patients with CSSD could explain some of these inconsistencies and that a study conducted with a very large number of HSs using visual naming tasks should strongly confirm the role of gender in categorical tasks.

Methods: Picture naming data gathered during the last ten years with our category-specificity paradigm from a large number (702) of HSs were reanalyzed.

Results: As predicted, men named significantly more animals and artifacts, while women named more plant life items.

Discussion: These data confirm that, if different domains of knowledge are studied in a very large sample of HSs using a picture naming task equivalent to the naming tasks used in most anatomo-clinical studies on CSSD, then the gender effects are highly significant.  相似文献   

8.
Airborne wind energy (AWE) refers to a novel technology capable of harvesting energy from wind by flying crosswind patterns with tethered autonomous aircraft. Successful design of flight controllers for AWE systems relies on the availability of accurate mathematical models. Due to an expected nonconventional structure of the airborne component, the system identification procedure must be ultimately addressed via an intensive flight test campaign to gain additional insight about the aerodynamic properties. In this paper, the longitudinal dynamics of a rigid‐wing, high lift, autonomous aircraft for AWE are identified from experimental data obtained within flight tests. The aerodynamic characteristics are estimated via an efficient time‐domain multiple experiments model‐based parameter estimation algorithm.  相似文献   
9.
Rapidly accumulating data from large‐scale cancer genomics studies have been generating important information about genes and their somatic alterations underlying cell transformation, cancer onset and tumor progression. However, these events are usually defined by using computational techniques, whereas the understanding of their actual functional roles and impact typically warrants validation by experimental means. Critical information has been obtained from targeted genetic perturbation (gene knockout) studies conducted in animals, yet these investigations are cost‐prohibitive and time‐consuming. In addition, the 3R principles (replacement, reduction, refinement) have been set in place to reduce animal use burden and are increasingly observed in many areas of biomedical research. Consequently, the focus has shifted to new designs of innovative cell‐based experimental models of cell immortalization and transformation in which the critical cancer driver events can be introduced by mutagenic insult and studied functionally, at the level of critical phenotypic readouts. From these efforts, primary cell‐based selective barrier‐bypass models of cell immortalization have emerged as an attractive system that allows studies of the functional relevance of acquired mutations as well as their role as candidate cancer driver events. In this review, we provide an overview of various experimental systems linking carcinogen exposure‐driven cell transformation with the study of cancer driver events. We further describe the advantages and disadvantages of the currently available cell‐based models while outlining future directions for in vitro modeling and functional testing of cancer driver events.  相似文献   
10.
Besides the design freedom offered by additive manufacturing, another asset lies within its potential to accelerate product development processes by rapid fabrication of functional prototypes. The premise to fully exploit this benefit for lightweight design is the accurate structural response prediction prior to part production. However, the peculiar material behavior, characterized by anisotropy, thickness dependency and scatter, still constitutes a major challenge. Hence, a modeling approach for finite element analysis that accounts for this inhomogeneous behavior is developed by example of laser-sintered short-fiber-reinforced polyamide 12. Orthotropic and thickness-dependent Young’s moduli and Poisson’s ratios were determined via quasi-static tensile tests. Thereof, material models were generated and implemented in a property mapping routine for finite element models. Additionally, a framework for stochastic finite element analysis was set up for the consideration of scatter in material properties. For validation, thin-walled parts on sub-component level were fabricated and tested in quasi-static three-point bending experiments. Elastic parameters showed considerable anisotropy, thickness dependency and scatter. A comparison of the predicted forces with experimentally evaluated reaction forces disclosed substantially improved accuracy when utilizing the novel inhomogeneous approach instead of conventional homogeneous approaches. Furthermore, the variability observed in the structural response of loaded parts could be reproduced by the stochastic simulations.  相似文献   
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