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   6239篇
  免费   779篇
  国内免费   447篇
耳鼻咽喉   56篇
儿科学   101篇
妇产科学   93篇
基础医学   696篇
口腔科学   130篇
临床医学   879篇
内科学   963篇
皮肤病学   52篇
神经病学   414篇
特种医学   263篇
外国民族医学   3篇
外科学   689篇
综合类   917篇
预防医学   421篇
眼科学   159篇
药学   634篇
  12篇
中国医学   524篇
肿瘤学   459篇
  2024年   21篇
  2023年   119篇
  2022年   358篇
  2021年   411篇
  2020年   319篇
  2019年   243篇
  2018年   271篇
  2017年   257篇
  2016年   243篇
  2015年   366篇
  2014年   396篇
  2013年   304篇
  2012年   432篇
  2011年   451篇
  2010年   313篇
  2009年   220篇
  2008年   271篇
  2007年   314篇
  2006年   287篇
  2005年   286篇
  2004年   208篇
  2003年   199篇
  2002年   187篇
  2001年   139篇
  2000年   150篇
  1999年   132篇
  1998年   86篇
  1997年   84篇
  1996年   70篇
  1995年   49篇
  1994年   59篇
  1993年   28篇
  1992年   32篇
  1991年   27篇
  1990年   30篇
  1989年   20篇
  1988年   18篇
  1987年   14篇
  1986年   11篇
  1985年   12篇
  1984年   6篇
  1983年   2篇
  1982年   5篇
  1981年   3篇
  1979年   5篇
  1974年   1篇
  1972年   1篇
  1968年   1篇
  1964年   1篇
  1957年   1篇
排序方式: 共有7465条查询结果,搜索用时 38 毫秒
141.
142.
Individuals with severe mental disorders continue to experience low employment rates. Occupational therapists play an important role in helping these individuals develop the skills and obtain the supports necessary for productive living. This retrospective cohort study aimed to explore employment outcomes and identify factors predictive of the outcomes of an in‐house prevocational training program designed for newly discharged psychiatric inpatients. Data retrieved from the files of 58 participants including demographics, diagnostic history, physical fitness, functional assessment results, the use of vocational counselling service and employment status were analyzed. The overall employment rates among the participants were high (67.2–79.3%) within the 6 months following the prevocational training program. No significant differences were found in the employment rates across the 1, 3 and 6‐month time periods post‐training. Vocational counselling service post‐training and hand function were two factors predictive of participants' employment outcomes. Occupational therapists should attend to the clients' need for continuous vocational support and carefully identify the personal, functional and environmental factors contributing to successful employment. Caution in interpreting the results is warranted because of the lack of control and randomization in this retrospective study. Additional longitudinal cohort or experimental studies would add further certainty to the current findings. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
143.
目的:利用LipofectamineTM2000将针对靶向人类端粒酶末端逆转录酶(hTERT)和Bax inhibitor‐1(Bi‐1)基因设计并构建的质粒载体转染至CNE‐2Z鼻咽癌细胞内,诱导序列特异性的基因沉默,研究其产生的shRNA阻抑hTERT 和Bi‐1基因表达的效果。方法收集CNE‐2Z细胞,设未处理组、pEGFP‐N1组、pEGFP‐N1/Lip组,采用流式细胞术检测Lip对CNE‐2Z细胞的转染能力,RT‐PCR和Western blot法分析表达shRNA重组质粒载体对hTERT和Bi‐1基因mRNA表达的抑制效应。结果转染CNE‐2Z细胞的质粒和Lip最佳组合:质粒为2.5μg ,Lip为6.25μL。结论成功构建的针对人hTERT和Bi‐1基因的shRNA真核表达质粒能特异、有效地阻抑hTERT和Bi‐1基因的表达。  相似文献   
144.
目的:观察针药结合治疗年龄相关性黄斑变性患者的临床疗效。方法:符合纳入标准的45例(69只眼)病例,随机分成对照组22例(34只眼)和治疗组23例(36只眼)。观察比较两组病例治疗前后患眼视力、眼底的改变,眼底荧光血管造影(FFA)、视野及Amsler的变化。结果:治疗后上述指标的改善情况,治疗组优于对照组(P0.01),尤其是视力明显改善。结论:从湿性年龄相关性黄斑变性的病因病机入手,采用针药结合的方法取得较好的临床疗效,值得进一步深入研究并推广利用。  相似文献   
145.
Background and Objectives: while existing research has demonstrated a positive association between exposure to point-of-sale (POS) tobacco advertising and youth smoking, there is limited evidence on the relationship between POS advertising restrictions and experimental smoking among youth. This study aims to fill this research gap by analyzing the association between POS advertising bans and youths'' experimental smoking. Methods: Global Youth Tobacco Surveys from 130 countries during 2007–2011 were linked to the WHO “MPOWER” tobacco control policy measures to analyze the association between POS advertising bans (a dichotomous measure of the existence of such bans) and experimental smoking using weighted logistic regressions. All analyses were clustered at the country level and controlled for age, parents'' smoking status, GDP per capita, and country-level tobacco control scores in monitoring tobacco use, protecting people from smoke, offering help to quit, warning about the dangers of tobacco, enforcing promotion/advertising bans, and raising taxes on tobacco. Results: The results suggest that a POS advertising ban is significantly associated with reduced experimental smoking among youth (OR = 0.63, p < 0.01), and that this association is seen for both genders (boys OR = 0.74, p < 0.1; girls OR = 0.52, p < 0.001). Conclusions: POS advertising bans are significantly associated with reduced experimental smoking among youth. Adopting POS advertising bans has the potential to reduce tobacco use among their youth in countries currently without such bans.  相似文献   
146.
目的探讨藤草煎治疗脑出血后抑郁的疗效。方法选取脑出血合并抑郁患者72例,随机分为对照组和治疗组,对照组给予氟哌噻吨美利曲辛治疗,治疗组给予藤草煎汤剂口服,分别于入选时、治疗3个月时采用神经功能缺损评分(NIHSS)和汉密尔顿抑郁量表(HAMD)进行评价。结果治疗3个月时2组患者NIHSS评分和HAMD评分与治疗前比较均明显降低(P<0.05);治疗组NIHSS评分优于对照组,差异有统计学意义(P<0.05),HAMD评分与对照组比较差异无统计学意义(P>0.05)。结论藤草煎治疗脑出血后抑郁具有明显的临床疗效。  相似文献   
147.
148.
Ultrathin 1T (tetragonal)-TaS2 and monolayer MoS2 heterostructures were prepared to study their phase transition (PT) mechanisms and band structure modulation. The temperature dependency of photoluminescence (PL) and Raman spectra was utilized to study interlayer coupling and band structure. The PL results indicate that the band structure of MoS2/TaS2 heterostructures undergoes a sharp change at 214 K. This is attributed to the PT of 1T-TaS2 from a Mott insulator state to a metastable state. In addition, the temperature dependency of the MoS2/TaS2 Raman spectra illustrates that the phonon vibration of the heterojunction is softened due to the effect of interlayer coupling. The present work could provide an avenue to create material systems with abundant functionalities and physical effects.

The important interlayer coupling of the MoS2–TaS2 heterostructure and the phase transition mechanism of ultrathin 1T-TaS2 are described.  相似文献   
149.
系统综述了海绵Axinella属的生物碱、三萜、甾体等化学成分,及其抗肿瘤、抗菌、神经保护等生物活性的研究进展,为该属海绵的深入研究提供有用资料。  相似文献   
150.
Lan  Siqin  He  Yuanlin  Tiheiran  Maijudan  Liu  Wenya  Guo  Hui 《Clinical rheumatology》2021,40(10):4289-4294
Clinical Rheumatology - The Angiopoietin-like protein 4 (ANGPTL-4) has been proved to be a protein associated with multiple inflammatory responses. Nevertheless, whether it contributes to...  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