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   144499篇
  免费   12668篇
  国内免费   896篇
耳鼻咽喉   569篇
儿科学   4582篇
妇产科学   5320篇
基础医学   11360篇
口腔科学   2375篇
临床医学   11556篇
内科学   30305篇
皮肤病学   2088篇
神经病学   10275篇
特种医学   3052篇
外国民族医学   1篇
外科学   15855篇
综合类   3326篇
现状与发展   8篇
一般理论   19篇
预防医学   34447篇
眼科学   1949篇
药学   5023篇
  7篇
中国医学   115篇
肿瘤学   15831篇
  2024年   51篇
  2023年   4739篇
  2022年   6460篇
  2021年   7435篇
  2020年   8569篇
  2019年   5682篇
  2018年   6835篇
  2017年   7215篇
  2016年   6852篇
  2015年   6946篇
  2014年   11588篇
  2013年   10174篇
  2012年   7124篇
  2011年   7194篇
  2010年   8279篇
  2009年   7681篇
  2008年   5467篇
  2007年   5181篇
  2006年   4509篇
  2005年   3978篇
  2004年   3374篇
  2003年   3287篇
  2002年   2828篇
  2001年   2698篇
  2000年   2399篇
  1999年   2206篇
  1998年   1233篇
  1997年   799篇
  1996年   675篇
  1995年   511篇
  1994年   486篇
  1993年   424篇
  1992年   909篇
  1991年   722篇
  1990年   712篇
  1989年   582篇
  1988年   487篇
  1987年   256篇
  1986年   119篇
  1985年   175篇
  1984年   159篇
  1983年   130篇
  1982年   111篇
  1981年   89篇
  1980年   101篇
  1979年   72篇
  1978年   64篇
  1977年   54篇
  1976年   56篇
  1974年   54篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
The discussion paper will focus on continuity of care relating to previous NZ research, specifically to transitioning complex preterm infants from NICU to home based on parent experiences, and on the practice developments that have occurred, to ensure optimal health outcomes. Previous NZ research discovered parent desire a consistent service delivery for the entire transition journey from NICU and at home.An informative and comprehensive opportunity has occurred for reflective professional practice, evaluation, development and implementation which have transpired in positive change through innovative practice developments and support change implementation in Wellington, NZ. This has resulted in the articulation of a model of care that has both embraced and integrated parental desires for a continuity of care process for complex preterm infants. This has been achieved by having the same Discharge Facilitator/Key Case Manager present within the NICU and external to the NICU for Home-based infants for the entire transition journey.The paper will focus and emphasis additional practice development changes and furthermore, will present a real purpose, for other countries to learn of such practice developments that have exemplified a celebratory success for families of Wellington, NZ.  相似文献   
5.
6.
The left atrial Reduction group revealed decreased risk of overall stroke compared to the left atrial Preservation group, adjusted by inverse probability of treatment weighting. Which implicates that reduction of left atrial wall during surgical ablation of atrial fibrillation may reduce the risk of stroke in patients with left atrial anteroposterior diameter ≥50 mm. Schematic illustration of left atrial reduction plasty, and IPTW-adjusted Kaplan-Meier survival plot for stroke comparing 2 groups are included in the graphical abstract. SVC, Superior vena cava; LAA, Left atrial appendage; PVs, Pulmonary veins; MV, Mitral valve; LA, Left atrium; IPTW, Inverse probability of treatment weighting.
  1. Download : Download high-res image (260KB)
  2. Download : Download full-size image
  相似文献   
7.
An accumulating body of evidence has associated exposure to greenspace with improved birth outcomes, including higher birth weight and lower risk of low birth weight; however, evidence on such association with in-utero fetal growth is scarce. We explored the influence of maternal exposure to residential greenspace and fetal growth in four INMA (Infancia y Medio Ambiente) Spanish birth cohorts (2003–2008), with 2,465 participants. Residential greenspace was characterised by the Normalised Difference Vegetation Index (NDVI) average across 100 m, 300 m, and 500 m buffers around the residence. Repeated ultrasound measurements of the abdominal circumference (AC), biparietal diameter (BPD), femur length (FL), and estimated fetal weight (EFW) were used. We created customised-generalised least squares models to evaluate associations of residential greenspace exposure on each fetal growth parameter, controlled for the relevant confounders. There were associations between the 500 m buffer and BPD, FL, and AC. We also found associations in the 300 m buffer and FL and AC. The associations in the 100 m buffer were null. Estimates were higher among participants with lower socioeconomic status. Mediation analyses found that air pollution might explain 15–37% of our associations. Mediation by physical activity was not observed. Greenspace exposure may be beneficial for fetal growth.  相似文献   
8.
BackgroundThe treatment of patients after mechanical ventilation of lungs suffering from a multi-species infection of the tracheobronchial tree can be complicated.. The situation is aggravated in patients with post-intubation tracheal stenosis, where infection plays a leading pathogenetic role in damage to the tracheal wall. As a result of such a pathological process, cicatricial stenosis of the trachea of purulent-inflammatory infectious genesis or infected tracheal stenosis (ITS) may occur.MethodsIn this work, we studied the possibility of photodynamic inactivation of pathogenic microbiota typical for patients with ITS using methylene blue (MB) as a photosensitizer.Results13 clinical isolates of 8 species of bacteria from 9 patients were susceptible to photodynamic inactivation with MB. 30 μM of MB at a light irradiation dose of 25 J/cm2 and incubation with MB for 15 min allows to completely inactivate bacteria found in the tracheobronchial secretions of patients with ITS.ConclusionsMB retains its optico-physical properties in the range of 3–30 μM and provides effective inactivation of isolated Gram-positive and Gram-negative bacteria, including multi- and pan-resistant to antibiotics.  相似文献   
9.
10.
Head and neck squamous cell carcinoma (HNSCC) is considered an immunosuppressive malignancy. Cross-talk between cancer cells and immune cells is modulated in part by CC ligand (CCL) chemokines, having a major effect on tumor progression. However, the predictive value and function of CCL family members in HNSCC have not been elucidated. Here, the predictive value of CCL members in cancer prognosis and Immune checkpoint blockade therapy response was investigated. CCL17 and CCL22 were screened as the key CCL chemokines in HNSCC through co-expression analysis. Further, the correlation between CCL17/CCL22 expression and cancer immune infiltration were evaluated based on TIMER and were validated by a set of scRNA-seq data. Moreover, the expression level of CCL17/CCL22 we evaluated to predict the response to Immune checkpoint blockade therapy in a panel of cancer types by using the TIDE database. Results indicated that CCL17/CCL22 had a high co-expression correlation and had a marginally statistical significance with the overall survival in HNSCC patients (P value = 0.057 and 0.055, respectively). Our findings showed high expression of CCL17/CCL22 was positively correlated with CD4+ T cell infiltration levels in HNSCCs and activate mTORC1 signaling pathway in CD4+ T cells. Further analysis from TIDE showed the high expression of CCL17/CCL22 might predict favorable responses to immune checkpoint blockade therapy in HNSCC patients. These findings provide an insight into the predictive roles of CCL17/CCL22 in HNSCC.  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