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   2319篇
  免费   200篇
  国内免费   5篇
耳鼻咽喉   34篇
儿科学   68篇
妇产科学   92篇
基础医学   330篇
口腔科学   33篇
临床医学   272篇
内科学   546篇
皮肤病学   58篇
神经病学   207篇
特种医学   39篇
外科学   283篇
综合类   7篇
一般理论   3篇
预防医学   239篇
眼科学   30篇
药学   100篇
中国医学   2篇
肿瘤学   181篇
  2024年   4篇
  2023年   52篇
  2022年   81篇
  2021年   185篇
  2020年   110篇
  2019年   141篇
  2018年   126篇
  2017年   91篇
  2016年   87篇
  2015年   105篇
  2014年   122篇
  2013年   137篇
  2012年   218篇
  2011年   192篇
  2010年   74篇
  2009年   61篇
  2008年   127篇
  2007年   108篇
  2006年   97篇
  2005年   72篇
  2004年   79篇
  2003年   76篇
  2002年   55篇
  2001年   12篇
  2000年   7篇
  1999年   5篇
  1998年   11篇
  1997年   12篇
  1996年   9篇
  1995年   4篇
  1994年   7篇
  1993年   3篇
  1992年   3篇
  1991年   3篇
  1989年   2篇
  1988年   5篇
  1987年   4篇
  1986年   6篇
  1984年   4篇
  1983年   2篇
  1982年   3篇
  1981年   3篇
  1980年   2篇
  1978年   2篇
  1964年   1篇
  1963年   1篇
  1962年   1篇
  1935年   2篇
  1934年   1篇
  1929年   1篇
排序方式: 共有2524条查询结果,搜索用时 15 毫秒
21.
The objective of the present review is to provide an overview of existing research that has reported on the association between posttraumatic stress disorder (PTSD) and ischemic heart disease. Specific focus is given to the incidence of PTSD following myocardial infarction (MI). A systematic review using Preferred Reporting Items for Systematic reviews and Meta‐Analysis (PRISMA) guidelines was performed by searching four bibliographic databases: PubMed, PsychINFO, ScienceDirect, and ProQuest Dissertations and Theses. A total of 39 articles were included in this literature review. The results of these studies suggest that the occurrence of an acute cardiac event is likely to contribute to the development of PTSD. Not only is this type of psychiatric disorder associated with significant suffering and impaired quality of life, but it is also a predictor of an increased risk of recurrent adverse cardiovascular events and mortality. Screening, assessment, and treatment of PTSD and posttraumatic stress symptoms following a major cardiac event are critical for offsetting potential deleterious psychological and physical consequences.  相似文献   
22.
Available data on clinical presentation and mortality of coronavirus disease-2019 (COVID-19) in heart transplant (HT) recipients remain limited. We report a case series of laboratory-confirmed COVID-19 in 39 HT recipients from 3 French heart transplant centres (mean age 54.4 ± 14.8 years; 66.7% males). Hospital admission was required for 35 (89.7%) cases including 14/39 (35.9%) cases being admitted in intensive care unit. Immunosuppressive medications were reduced or discontinued in 74.4% of the patients. After a median follow-up of 54 (19–80) days, death and death or need for mechanical ventilation occurred in 25.6% and 33.3% of patients, respectively. Elevated C-reactive protein and lung involvement ≥50% on chest computed tomography (CT) at admission were associated with an increased risk of death or need for mechanical ventilation. Mortality rate from March to June in the entire 3-centre HT recipient cohort was 56% higher in 2020 compared to the time-matched 2019 cohort (2% vs. 1.28%, P = 0.15). In a meta-analysis including 4 studies, pre-existing diabetes mellitus (OR 3.60, 95% CI 1.43–9.06, I2 = 0%, P = 0.006) and chronic kidney disease stage III or higher (OR 3.79, 95% CI 1.39–10.31, I2 = 0%, P = 0.009) were associated with increased mortality. These findings highlight the aggressive clinical course of COVID-19 in HT recipients.  相似文献   
23.
BackgroundPrevious data has shown that severe traumatic injury is associated with bone marrow dysfunction, which manifests as persistent injury-associated anemia. This study sought to identify whether the expression of erythropoiesis-related microRNAs were altered in the bone marrow of trauma patients to determine if these microRNAs play a role in persistent injury-associated anemia.MethodsBone marrow was collected from severely injured trauma patients who underwent fracture fixation as well as patients who underwent elective hip replacement. There were 27 trauma patients and 10 controls analyzed. Total RNA and microRNA were isolated from CD34-positive cells using the RNeasy Plus Mini kit, and genome-wide microRNA expression patterns were assayed. Genes with significant expression differences were found using BRB-ArrayTools with a significance of P < .01.ResultsThere were marked differences in expression of 108 microRNAs in the trauma group when compared with hip replacement patients. Four of these microRNAs play a role in regulating erythropoiesis: microRNA-150, microRNA-223, microRNA15a, and microRNA-24. These microRNAs were all upregulated significantly, with trauma/hip replacement fold changes of 1.7, 1.8, 1.2, and 1.2 respectively, and all act to suppress or regulate erythropoiesis.ConclusionAssessment of the bone marrow microRNA profile in trauma patients compared to those undergoing elective hip replacement revealed the differential expression of microRNA-150, microRNA-223, microRNA-15a, and microRNA-24. These microRNAs all play a role in decreased erythroid progenitor cell growth and provide important insight to the erythropoietic dysfunction seen after trauma.  相似文献   
24.
Controlled donation after circulatory death (cDCD) is used for “extended criteria” donors with poorer kidney transplant outcomes. The French cDCD program started in 2015 and is characterized by normothermic regional perfusion, hypothermic machine perfusion, and short cold ischemia time. We compared the outcomes of kidney transplantation from cDCD and brain-dead (DBD) donors, matching cDCD and DBD kidney transplants by propensity scoring for donor and recipient characteristics. The matching process retained 442 of 499 cDCD and 809 of 6185 DBD transplantations. The DGF rate was 20% in cDCD recipients compared with 28% in DBD recipients (adjusted relative risk [aRR], 1.43; 95% confidence interval [CI] 1.12–1.82). When DBD transplants were ranked by cold ischemia time and machine perfusion use and compared with cDCD transplants, the aRR of DGF was higher for DBD transplants without machine perfusion, regardless of the cold ischemia time (aRR with cold ischemia time <18 h, 1.57; 95% CI 1.20–2.03, vs aRR with cold ischemia time ≥18 h, 1.79; 95% CI 1.31–2.44). The 1-year graft survival rate was similar in both groups. Early outcome was better for kidney transplants from cDCD than from matched DBD transplants with this French protocol.  相似文献   
25.
Growing interest surrounds adoptive cellular therapies utilizing Natural Killer (NK) cells, which can be obtained from various sources, including umbilical cord blood (UCB) and adult peripheral blood (APB). Understanding NK cell receptor expression and diversity in such cellular sources will guide future therapeutic designs. We used a 20-color flow cytometry panel to compare unstimulated and cytokine-activated UCB and APB NK cells. Our analysis showed that UCB NK cells express slightly higher levels of the immune checkpoints PD-1, TIGIT, and CD96 compared to their APB counterparts. Unsupervised hierarchical clustering and dimensionality reduction analyses revealed enrichment in CD56neg as well as mature NKp46neg and CD56+CD16+ NK cell populations in UCB whereas CD57+ terminally differentiated NK cells with variable expression of KIRs and CD16 were found in APB. These populations were conserved following stimulation with IL-12, IL-15, and IL-18. Cytokine stimulation was associated with the downregulation of TIGIT and CD16 on multiple NK cell subsets in UCB and APB. Among UCB CD16 NK cell populations, TIGIT+ NK cells produced more IFN-γ than their TIGIT counterparts. Our data demonstrate higher immune checkpoint expression on UCB NK cells compared to APB. However, the expression of TIGIT immune checkpoint is not indicative of NK cell exhaustion.  相似文献   
26.
27.
28.
Depressive disorder is a common consequence of interferon α treatment. An understanding of the aetiological processes involved is evolving. HPA axis abnormalities are clearly described in community depressive disorder and represent vulnerability to depression development. We explored whether pre-treatment HPA axis abnormalities influence depression emergence during interferon α treatment. We examined waking HPA axis response via salivary cortisol sampling in 44 non-depressed, chronic hepatitis C infected patients due to commence standard interferon α treatment. Hamilton depression scales and the structured clinical interview for DSM-IV major depressive disorder status were administered monthly during treatment. Major depressive disorder developed in 26 of 44 subjects during interferon-α treatment. The pre-treatment waking cortisol response over 1 h was significantly greater in the subsequent switch to depression group (F=4.23, p=0.046). The waking cortisol response pre-treatment with interferon α appears greater in those subsequently switching to depressive disorder during treatment. This waking response may join other vulnerability factors for depression emergence in this group. This model could prove a valuable tool in understanding non-iatrogenic depressive disorder in the general population and notably the role of cytokines.  相似文献   
29.
Aims: This pilot randomized comparative study investigated changes in motor performance and indices of neuroplasticity associated with occupation-based intervention and repetitive task practice in the recovery of occupational performance following stroke. Method: Sixteen participants received either occupation-based intervention or repetitive task practice for eight 55-minute sessions. Motor performance was measured by the Fugl Meyer Assessment (FMA), Stroke Impact Scale (SIS), the Canadian Occupational Performance Measure (COPM) and the Goal Attainment Scale (GAS). Indices of neuroplastic change were assessed by transcranial magnetic stimulation (TMS). Results: Both occupation-based intervention and repetitive task practice groups demonstrated significant changes on the FMA and the occupation-based group demonstrated significant changes on the GAS goals. Neurophysiological measures showed enlargement in TMS volume maps in the affected hemisphere for both groups. Conclusion: Occupation-based and repetitive task practice interventions can yield similar improvements in chronic stroke.  相似文献   
30.
Physical activity is partly regulated by automatic processes such as habits (ie, well-learned responses to cues), but it remains unclear what cues trigger these processes. This study examined the relations of physical activity automaticity and behavior with the consistency of people, activity, routine, location, time, and mood cues present upon initiation of physical activity behavior. Australian adults (N = 1,244, 627 female, M age = 55 years) reported their physical activity automaticity, behavior, and the degree of consistency of these cues each time they start a physical activity behavior. Multiple regression models, which accounted for gender and age, revealed that more consistent routine and mood cues were linked to more physical activity automaticity; whereas more consistent time and people cues were linked to more physical activity behavior. Interventions may more effectively translate into long-lasting physical activity habits if they draw people's attention to the salient cues of time, people, routine, and mood.  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