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   2776篇
  免费   242篇
  国内免费   41篇
耳鼻咽喉   24篇
儿科学   65篇
妇产科学   23篇
基础医学   493篇
口腔科学   31篇
临床医学   414篇
内科学   431篇
皮肤病学   22篇
神经病学   141篇
特种医学   280篇
外科学   395篇
综合类   102篇
预防医学   233篇
眼科学   9篇
药学   192篇
中国医学   3篇
肿瘤学   201篇
  2022年   18篇
  2021年   32篇
  2020年   25篇
  2019年   36篇
  2018年   56篇
  2017年   36篇
  2016年   27篇
  2015年   54篇
  2014年   70篇
  2013年   88篇
  2012年   172篇
  2011年   167篇
  2010年   82篇
  2009年   76篇
  2008年   111篇
  2007年   146篇
  2006年   112篇
  2005年   105篇
  2004年   109篇
  2003年   105篇
  2002年   93篇
  2001年   79篇
  2000年   80篇
  1999年   68篇
  1998年   44篇
  1997年   39篇
  1996年   31篇
  1995年   40篇
  1994年   28篇
  1993年   23篇
  1992年   72篇
  1991年   50篇
  1990年   55篇
  1989年   64篇
  1988年   48篇
  1987年   65篇
  1986年   44篇
  1985年   50篇
  1984年   39篇
  1983年   32篇
  1982年   27篇
  1981年   29篇
  1979年   28篇
  1978年   27篇
  1977年   17篇
  1976年   23篇
  1975年   28篇
  1974年   30篇
  1973年   23篇
  1968年   17篇
排序方式: 共有3059条查询结果,搜索用时 15 毫秒
1.
Lesbian, gay, bisexual, transgender, queer and two-spirit plus (LGBTQ2S+) people have distinct healthcare needs that may be unaddressed in many undergraduate healthcare curricula. The Radiation Therapy Program (RADTH) at the University of Alberta underwent a review of the three-year didactic curriculum using an online survey. The survey sought to ascertain if, where and how topics related to LGBTQ2S + healthcare are taught. Results indicated that out of 10 RADTH program faculty respondents, three teach related topics. The total time dedicated within the three-year curriculum was approximately three and a half hours. Other findings showed that faculty are interested in receiving more education in this area and would favour discussions about how to incorporate these themes into appropriate courses. This preliminary investigation demonstrated that there has been some initial work in this area, but there is more to be done.  相似文献   
2.
Background Immune checkpoint blockers (ICBs) activate CD8+ T cells, eliciting both anti-cancer activity and immune-related adverse events (irAEs). The relationship of irAEs with baseline parameters and clinical outcome is unclear.Methods Retrospective evaluation of irAEs on survival was performed across primary (N = 144) and secondary (N = 211) independent cohorts of patients with metastatic melanoma receiving single agent (pembrolizumab/nivolumab—sICB) or combination (nivolumab and ipilimumab—cICB) checkpoint blockade. RNA from pre-treatment and post-treatment CD8+ T cells was sequenced and differential gene expression according to irAE development assessed.Results 58.3% of patients developed early irAEs and this was associated with longer progression-free (PFS) and overall survival (OS) across both cohorts (log-rank test, OS: P < 0.0001). Median survival for patients without irAEs was 16.6 months (95% CI: 10.9–33.4) versus not-reached (P = 2.8 × 10−6). Pre-treatment monocyte and neutrophil counts, but not BMI, were additional predictors of clinical outcome. Differential expression of numerous gene pathway members was observed in CD8+ T cells according to irAE development, and patients not developing irAEs demonstrating upregulated CXCR1 pre- and post-treatment.Conclusions Early irAE development post-ICB is associated with favourable survival in MM. Development of irAEs is coupled to expression of numerous gene pathways, suggesting irAE development in-part reflects baseline immune activation.Subject terms: Immunotherapy, Melanoma  相似文献   
3.
Uniparental isodisomy (iUPD) is a rare genetic condition caused by non-disjunction during meiosis that ultimately leads to a duplication of either the maternal or paternal chromosome in the affected individual. Two types of disorders can result, those due to imprinted genes and those due to homozygosity of recessive disease-causing mutations. Here, we describe the third known case of complete chromosome 4 iUPD of maternal origin. This condition became apparent during whole genome linkage studies of psychiatric disorders in the Portuguese population. The proband is an adult female with normal fertility and no major medical complaints, but a history of major depressive disorder and multiple suicide attempts. The proband's siblings and parents had normal chromosome 4 genotypes and no history of mood disturbance. A brief review of other studies lends support for the possibility that genes on chromosome 4 might confer risk for mood disorders. We conclude that chromosome 4 maternal uniparental disomy (UPD) is a rare disorder that may present with a major depressive phenotype. The lack of a common disease phenotype between this and two other cases of chromosome 4 iUPD [Lindenbaum et al. [1991] Am J Med Genet 49(Suppl 285):1582; Spena et al. [2004] Eur J Hum Genet 12:891-898) would suggest that there is no vital maternal gene imprinting on chromosome 4. However, since there is no reported case of paternal chromosome 4 UPD, paternal gene imprinting on chromosome 4 cannot be excluded.  相似文献   
4.
5.
From 1970 to 1980, 153 patients with stages A2, B1 and B2 prostatic cancer and proved negative pelvic lymph nodes underwent radical prostatectomy (84 underwent radical perineal and 69 underwent radical retropubic prostatectomy). Seventeen patients were lost to followup. Of 136 patients who were followed for 5 years or until death 128 (94 per cent) were alive at 5 years, including 118 (87 per cent) who were without evidence of recurrence. Patients with microscopic invasion of the prostatic capsule have a better outcome at 5 years than those with microscopic involvement of the seminal vesicles. Only 46 of the patients could be assessed at 10 years or had died 6 to 10 years postoperatively. Results at 10 years are considered preliminary, since many more patients will reach the 10-year milestone within the next few years.  相似文献   
6.
7.
8.
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.  相似文献   
9.
The oxygen-sensitive bioreductive binding of 2-nitroimidazoles labeled with fluorescent side chains has been used to stain hypoxic mammalian cells selectively. Several novel compounds were synthesized with a 1-substituent containing a fluorescent, bicyclic system having a bridgehead-nitrogen atom. Additional amine and secondary alcohol substituents were also included in the link between the fluorophor and the nitroimidazole to improve water solubility. Their ability to discriminate between hypoxic and oxic cells was compared by flow cytometric analysis. A wide range of cellular fluorescence and hypoxic-oxic differentials in fluorescence was observed when compounds with indolizine fluorophors were incubated with cells, and one such compound was considered suitable for further evaluation in vivo. Two compounds with bimane fluorophors gave very little cellular fluorescence when incubated with hypoxic cells.  相似文献   
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