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   9502篇
  免费   918篇
  国内免费   332篇
耳鼻咽喉   227篇
儿科学   131篇
妇产科学   194篇
基础医学   1733篇
口腔科学   182篇
临床医学   703篇
内科学   1610篇
皮肤病学   281篇
神经病学   365篇
特种医学   241篇
外国民族医学   2篇
外科学   609篇
综合类   1034篇
现状与发展   4篇
预防医学   767篇
眼科学   89篇
药学   1411篇
  8篇
中国医学   692篇
肿瘤学   469篇
  2024年   16篇
  2023年   175篇
  2022年   163篇
  2021年   494篇
  2020年   371篇
  2019年   342篇
  2018年   381篇
  2017年   369篇
  2016年   327篇
  2015年   401篇
  2014年   565篇
  2013年   769篇
  2012年   501篇
  2011年   560篇
  2010年   489篇
  2009年   429篇
  2008年   450篇
  2007年   391篇
  2006年   355篇
  2005年   355篇
  2004年   305篇
  2003年   250篇
  2002年   243篇
  2001年   214篇
  2000年   191篇
  1999年   174篇
  1998年   180篇
  1997年   109篇
  1996年   127篇
  1995年   126篇
  1994年   127篇
  1993年   90篇
  1992年   88篇
  1991年   87篇
  1990年   67篇
  1989年   73篇
  1988年   47篇
  1987年   46篇
  1986年   43篇
  1985年   79篇
  1984年   44篇
  1983年   39篇
  1982年   35篇
  1981年   18篇
  1980年   13篇
  1979年   12篇
  1978年   6篇
  1977年   4篇
  1976年   5篇
  1972年   3篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
1.
ABSTRACT

Introduction

Acne is a chronic, inflammatory, and immune mediated disease of pilosebaceous unit, highly prevalent in adolescents. It involves face, trunk, and back; may leave scars and affect quality of life. Early, effective, and safe treatment is the key for disease resolution. Oral isotretinoin is the unique treatment for cure or prolonged remission for moderate and severe acne, preventing psychosocial impact and scars. It inhibits sebaceous glands activity and has anti-inflammatory and immunoregulatory properties.  相似文献   
2.
3.
This work aimed at developing a new soy-based beverage and studying the influence of formulation ingredients on its antioxidants, physicochemical, and sensory properties. For this purpose, mixed beverages with lemongrass, lime juice, and soymilk were formulated. Soy-based beverages showed differences in pH, ratio, and color as compared to mixed beverages without soy. Soymilk increased the phenolics content and the ABTS antioxidant capacity, while lemongrass aqueous extract increased the DPPH antioxidant capacity of soy-based beverages. The new soy-based beverage had good acceptance for all attributes and can be considered a viable alternative source of nutrients and bioactive compounds to consumers.  相似文献   
4.
目的利用翻转课堂教学法改进传统的天然药物化学实验课教学模式,提高该课程的教学效果。方法从实验教学的课程设计与开发,课前自主学习、课中内化及课后评估和讨论等环节进行了一系列的探讨与改革。结果翻转课堂教学模式为解决学生长期以来在天然药物化学实验课中缺乏主动参与性、探索性等问题提供一剂良方。结论在天然药物化学实验课教学中引入翻转课堂教学模式的初步探索为天然药物化学实验课的改革提供了依据和思路。  相似文献   
5.
B cells are recognized as the main effector cells of humoral immunity which suppress tumor progression by secreting immunoglobulins, promoting T cell response, and killing cancer cells directly. Given these properties, their anti-tumor immune response in the tumor micro-environment (TME) is of great interest. Although T cell-related immune responses have become a therapeutic target with the introduction of immune checkpoint inhibitors, not all patients benefit from these treatments. B cell and B cell-related pathways (CCL19, −21/CCR7 axis and CXCL13/CXCR5 axis) play key roles in activating immune response through humoral immunity and local immune activation via tertiary lymphoid structure (TLS) formation. However they have some protumorigenic works in the TME. Thus, a better understanding of B cell and B cell-related pathways is necessary to develop effective cancer control. In this review, we summarize recent evidences regarding the roles of B cell and B cell-related pathways in the TME and immune response and discuss their potential roles for novel cancer treatment strategies.  相似文献   
6.
《The Journal of arthroplasty》2021,36(9):3118-3122
BackgroundThis study aimed to assess the baseline levels of D-dimer, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) and monitor the natural course of these serum markers after uneventful primary total joint arthroplasty.MethodsThis prospective study enrolled 81 patients undergoing primary total knee arthroplasty or total hip arthroplasty. The level of serum D-dimer, CRP, and ESR was measured preoperatively and on postoperative days 1, 3, 5, 15, and 45. Mean peak values, peak times, and distribution were compared between D-Dimer, CRP, and ESR.ResultsThe mean preoperative serum D-dimer, CRP, and ESR level was 412 ± 260 (range 200-980) ng/mL, 2.93 ± 2.1 (range 1-18) mg/L, and 22.88 ± 17.5 (range 3-102) mm/h, respectively. The highest mean peak for D-dimer, CRP, and ESR was at postoperative day 1, 3, and 5, respectively.ConclusionD-dimer levels reached peak levels on postoperative day 1 and then declined rapidly to a plateau level by postoperative day 3. A second, albeit small, peak in the level of D-dimer occurred on postoperative day 15. The level of CRP and ESR remained elevated for much longer with CRP returning to baseline on postoperative day 45 and the level of ESR had not returned back to normal on postoperative day 45.  相似文献   
7.
Considering the relatively high heritability of schizophrenia and the fact that it significantly reduces the reproductive fitness of affected individuals, it is not clear how the disorder is still maintained in human populations at a disproportionally high prevalence. Many theories propose that the disorder is a result of a trade‐off between costs and benefits of the evolution of exclusively human adaptations. There have also been suggestions that schizophrenia risk alleles are accompanied with increase in fitness of affected persons or their relatives in both past and current social contexts. The discoveries of novel schizophrenia‐related genes and the advancements in comparative genomics (especially comparisons of the human genome and the genomes of related species, such as chimpanzees and extinct hominids) have finally made certain evolutionary theories testable. In this paper, we review the current understanding of the genetics of schizophrenia, the basic principles of evolution that complement our understanding of the subject, and the latest genetic studies that examine long‐standing evolutionary theories of schizophrenia using novel methodologies and data. We find that the origin of schizophrenia is complex and likely governed by different evolutionary mechanisms that are not mutually exclusive. Furthermore, the most recent evidence implies that schizophrenia cannot be comprehended as a trait that has elevated fitness in human evolutionary lineage, but has been a mildly deleterious by‐product of specific patterns of the evolution of the human brain. In other words, novel findings do not support previous hypotheses stating that schizophrenia risk genes have an evolutionary advantage.  相似文献   
8.
组织工程技术通过利用支架材料、种子细胞、生长因子以达到修复或再生组织器官的目的。支架材料的作用是为种子细胞提供机械支撑并且保护细胞免受体内有害微环境的影响。因此,选择或制备适当的支架材料是组织工程中的关键一步。近年来,将支架材料和牙龈间充质干细胞(gingival mesenchymal stem cells,GMSCs)联合应用于组织工程的研究逐渐走向成熟。本文就组织工程中牙龈间充质干细胞递送支架载体的研究现状进行综述,以期为GMSCs组织工程递送支架载体材料的开发和选择提供思路。  相似文献   
9.
10.
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