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   16090篇
  免费   1519篇
  国内免费   940篇
耳鼻咽喉   146篇
儿科学   161篇
妇产科学   293篇
基础医学   2001篇
口腔科学   265篇
临床医学   2139篇
内科学   2610篇
皮肤病学   182篇
神经病学   841篇
特种医学   564篇
外国民族医学   5篇
外科学   1903篇
综合类   2134篇
现状与发展   1篇
一般理论   6篇
预防医学   1073篇
眼科学   483篇
药学   1648篇
  15篇
中国医学   741篇
肿瘤学   1338篇
  2024年   45篇
  2023年   241篇
  2022年   577篇
  2021年   787篇
  2020年   552篇
  2019年   545篇
  2018年   554篇
  2017年   502篇
  2016年   490篇
  2015年   713篇
  2014年   868篇
  2013年   812篇
  2012年   1162篇
  2011年   1167篇
  2010年   843篇
  2009年   656篇
  2008年   771篇
  2007年   787篇
  2006年   821篇
  2005年   767篇
  2004年   638篇
  2003年   616篇
  2002年   572篇
  2001年   448篇
  2000年   387篇
  1999年   393篇
  1998年   272篇
  1997年   240篇
  1996年   179篇
  1995年   181篇
  1994年   114篇
  1993年   97篇
  1992年   109篇
  1991年   93篇
  1990年   72篇
  1989年   69篇
  1988年   65篇
  1987年   62篇
  1986年   42篇
  1985年   42篇
  1984年   22篇
  1983年   14篇
  1981年   14篇
  1980年   12篇
  1979年   21篇
  1976年   10篇
  1974年   15篇
  1973年   13篇
  1972年   10篇
  1969年   11篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
The role of mPer1 in morphine dependence in mice   总被引:6,自引:0,他引:6  
Liu Y  Wang Y  Wan C  Zhou W  Peng T  Liu Y  Wang Z  Li G  Cornelisson G  Halberg F 《Neuroscience》2005,130(2):383-388
Investigations using Drosophila melanogaster have shown that the circadian clock gene period can influence behavioral responses to cocaine, and the mouse homologues, mPer1 and mPer2, modulate cocaine sensitization and reward. In the present study, we applied DNAzyme targeting mPer1 to interfere the expression of mPer1 in CNS in mice and studied the role of mPer1 on morphine dependence. We found that the DNAzyme could attenuate the expression of mPer1 in CNS in mice. Mice treated with DNAzyme and morphine synchronously did not show preference to the morphine-trained side, whereas the control group did. In contrast, mice treated with DNAzyme after morphine showed preference to the morphine-trained side as well as the control group did. These results indicate that drug dependence seems to be influenced at least partially by mPer1, but mPer1 cannot affect morphine dependence that has been formed.  相似文献   
132.
133.
Background: The coronavirus disease 2019 (COVID-19) pandemic has increased the already high levels of stress that higher education students experience. Stress influences health behaviors, including those related to dietary behaviors, alcohol, and sleep; yet the effects of stress can be mitigated by resilience. To date, past research studying the connections between dietary behaviors, alcohol misuse, sleep, and resilience commonly investigated singular relationships between two of the constructs. The aim of the current study was to explore the relationships between these constructs in a more holistic manner using mediation and moderation analyses. Methods: Higher education students from China, Ireland, Malaysia, South Korea, Taiwan, the Netherlands, and the United States were enrolled in a cross-sectional study from April to May 2020, which was during the beginning of the COVID-19 pandemic for most participants. An online survey, using validated tools, was distributed to assess perceived stress, dietary behaviors, alcohol misuse, sleep quality and duration, and resilience. Results: 2254 students completed the study. Results indicated that sleep quality mediated the relationship between perceived stress and dietary behaviors as well as the relationship between perceived stress and alcohol misuse. Further, increased resilience reduced the strength of the relationship between perceived stress and dietary behaviors but not alcohol misuse. Conclusion: Based on these results, higher education students are likely to benefit from sleep education and resilience training, especially during stressful events.  相似文献   
134.
ObjectivesTo evaluate the effect of Hospital Admission Risk Program (HARP) on unplanned hospitalization, bed days, and mortality of enrolled individuals and to evaluate the cost-effectiveness of HARP.DesignA retrospective longitudinal analysis of hospital administrative data.InterventionIndividuals at risk of hospitalization were provided with multidisciplinary, community-based care support managed by care coordinators including integrated care planning, education, monitoring, service linkages, and general practitioner liaison over 6-9 months.Setting and ParticipantsIndividuals who were enrolled into 1 of 8 HARP chronic disease management programs between July 1, 2017, and June 30, 2018, at the Royal Melbourne Hospital, Australia.MethodsHospital admissions between 18 months before and 18 months after HARP enrollment were analyzed. Total hospital costs were compared between 18 months before and 12 months after HARP enrollment.ResultsA total of 1553 individuals with a median age of 71 years (interquartile range 60-81), 63.4% males, were admitted to HARP. Both unplanned hospitalizations and bed days were reduced during the HARP intervention compared to within 3 months before enrollment in each of the HARP management programs. After the HARP intervention, cardiac coach, cardiac heart failure, chronic respiratory, diabetes comanagement, and medication management programs had higher hospitalizations and bed days than individuals’ baseline of at least 3 months before HARP enrollment. Individuals in cardiac heart failure and chronic respiratory management programs had a higher mortality rate than other HARP chronic disease management programs. Individuals in cardiac coach, diabetes comanagement, and medication management programs had lower hospital costs during the HARP intervention compared to within 3 months before HARP enrollment.Conclusions and ImplicationsHARP reduced unplanned hospitalization and bed days but did not return individuals’ hospital use to baseline before the intervention. The variations in mortality between HARP chronic disease management programs implies that condition-specific goals between programs is preferable.  相似文献   
135.
目的探讨肝包虫合并乙型肝炎病毒(HBV)感染患者辅助性T细胞17(Th17)、CD4+细胞表面程序性死亡分子-1/程序性死亡分子1配体(PD-1/PD-L1)的表达水平及其临床意义。方法选取2014年9月一2019年9月新疆医科大学第一附属医院收治的肝包虫病患者作为研究对象﹐其中100例肝包虫病合并HBV感染患者为合并HBV感染组,肝包虫病无HBV感染患者88例为非HBV感染组﹐采用流式细胞仪检测外周血Th17,CD4+细胞表面PD-1,PD-L1表达水平。结果合并HBV感染组患者乙型肝炎家族史,B~C Child分级占比均高于非HBV感染组(P<0.05);肝功能指标[谷丙转氨酶(ALT)、谷草转氨酶(AST),γ-谷氨酰转肽酶(γ-GT)]水平以及Th17 PD-1、Th17 PD-L1,CD,PD-1,CD4+PD-L1表达水平均高于非HBV感染组(P<0.05);Child分级A级肝包虫病患者的Th17 PD-1,Th17 PD-L1,CD4+PD-1,CD4+PD-L1表达水平均低于Child分级B~C级患者(P<0.05)。结论HBV感染会影响肝包虫病患者的肝功能及外周血Th17,CD4+细胞表面PD-1,PD-L1表达水平,肝功能严重程度可能与外周血Th17,CD4+细胞PD-1,PD-L1表达存在关系。  相似文献   
136.
We investigated the kinetics of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies in 7 asymptomatic persons and 11 patients with pneumonia. The geometric mean titer of neutralizing antibodies declined from 219.4 at 2 months to 143.7 at 5 months after infection, indicating a waning antibody response.  相似文献   
137.
138.
目的:探讨治疗创伤对高血压性脑出血患者血糖及按期预后的影响。方法:采用局麻血肿穿刺抽吸治疗(治疗组32例)及全麻外科手术血肿清除治疗(对照组30例),比较术后的血糖变化,结果:治疗组血肿穿刺抽吸后血糖高峰值水平显著低于对照组(P<0.01),而治疗后第1,2,周血糖降至正常者治疗组显著高于对照组(P<0.05),病死率治疗组6.25%,对照组26.7%),两组比较差异显著(P<0.05),结论:高血压性脑出血患者血肿穿刺抽吸治疗较外科手术血肿清除治疗有血糖峰值低,恢复正常的速度快,病死率低,对脑组织的损伤小等优点,值得临床推广。  相似文献   
139.
目的:通过对骨髓单个核细胞在体外与不同细胞因子培养,了解不同细胞因子对骨髓淋巴细胞的激活能力和对骨髓干祖细胞的损伤情况。方法:将IL-1、IL-2、γ-IFN、CD3单抗进行不同组合后,在体外与骨髓单个核细胞分成对照组、IL-2组、CD3-AK、CIK组进行培养。培养过程中观察细胞形态和数量的变化,并在培养后检测免疫活性细胞的细胞毒性和造血干细胞的保存情况。结果:培养过程中对照组细胞数量减少;IL-2组细胞数量变化不明显;CD3-AK组、CIK组细胞数量显著增多,并出现较多的集聚成簇的淋巴样细胞,培养后其细胞毒性明显强于对照组及IL-2组,但细胞数量增加和细胞毒性无明性差异,培养后各组造血干细胞保存情况约16%~87%。结论:IL-2、CD3单抗在体外与骨髓单个核细胞培养后,即能激活免疫细胞增殖,又能保留足够的造血干细胞。  相似文献   
140.
夹竹桃水提物灭螺活性研究   总被引:3,自引:0,他引:3  
目的 研究夹竹桃水提物的灭螺活性。方法 测试水提物作用后钉螺的死亡率,用直线回归法进行量效和时效分析。结果 夹竹桃水提物灭螺的量效和时效关系分别为Y=95.4378D-21.2478和Y=21.32T-3.96,pH从5.5到8.5的范围内其活性随pH上升略有下降,室内贮存1年及100℃加热2h其活性基本不变。结论 夹竹桃水提物具有很强的灭螺活性。  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