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   5734篇
  免费   301篇
  国内免费   12篇
耳鼻咽喉   34篇
儿科学   409篇
妇产科学   82篇
基础医学   479篇
口腔科学   197篇
临床医学   343篇
内科学   1194篇
皮肤病学   304篇
神经病学   301篇
特种医学   171篇
外科学   813篇
综合类   460篇
预防医学   261篇
眼科学   286篇
药学   440篇
  1篇
中国医学   12篇
肿瘤学   260篇
  2023年   32篇
  2022年   26篇
  2021年   148篇
  2020年   82篇
  2019年   156篇
  2018年   194篇
  2017年   133篇
  2016年   161篇
  2015年   189篇
  2014年   232篇
  2013年   247篇
  2012年   404篇
  2011年   468篇
  2010年   292篇
  2009年   223篇
  2008年   290篇
  2007年   326篇
  2006年   250篇
  2005年   220篇
  2004年   213篇
  2003年   159篇
  2002年   183篇
  2001年   134篇
  2000年   130篇
  1999年   109篇
  1998年   66篇
  1997年   48篇
  1996年   45篇
  1995年   52篇
  1994年   38篇
  1993年   21篇
  1992年   76篇
  1991年   65篇
  1990年   42篇
  1989年   42篇
  1988年   59篇
  1987年   44篇
  1986年   39篇
  1985年   43篇
  1984年   30篇
  1983年   24篇
  1981年   17篇
  1979年   23篇
  1977年   17篇
  1974年   27篇
  1973年   16篇
  1972年   28篇
  1971年   19篇
  1969年   16篇
  1968年   18篇
排序方式: 共有6047条查询结果,搜索用时 31 毫秒
1.
Raghib syndrome is a rare developmental complex consisting of termination of the left superior vena cava in the left atrium, absence of the coronary sinus, and an atrial septal defect commonly located at the posterior‐inferior angle of the atrial septum. This complex was considered unique to Raghib syndrome; however, cases with a normal atrial septum have been reported where the orifice of the unroofed coronary sinus functions as the inter‐atrial communication. Our patient demonstrated an isolated persistent left superior vena cava draining into the left atrium through unroofed coronary sinus and presence of ostium primum atrial septal defect.  相似文献   
2.
The efforts for the development and testing of vaccines against Trypanosoma cruzi infection have increased during the past years. We have designed a TcVac series of vaccines composed of T. cruzi derived, GPI-anchored membrane antigens. The TcVac vaccines have been shown to elicit humoral and cellular mediated immune responses and provide significant (but not complete) control of experimental infection in mice and dogs. Herein, we aimed to test two immunization protocols for the delivery of DNA-prime/DNA-boost vaccine (TcVac1) composed of TcG2 and TcG4 antigens in a BALB/c mouse model. Mice were immunized with TcVac1 through intradermal/electroporation (IDE) or intramuscular (IM) routes, challenged with T. cruzi, and evaluated during acute phase of infection. The humoral immune response was evaluated through the assessment of anti-TcG2 and anti-TcG4 IgG subtypes by using an ELISA. Cellular immune response was assessed through a lymphocyte proliferation assay. Finally, clinical and morphopathological aspects were evaluated for all experimental animals. Our results demonstrated that when comparing TcVac1 IDE delivery vs IM delivery, the former induced significantly higher level of antigen-specific antibody response (IgG2a?+?IgG2b?>?IgG1) and lymphocyte proliferation, which expanded in response to challenge infection. Histological evaluation after challenge infection showed infiltration of inflammatory cells (macrophages and lymphocytes) in the heart and skeletal tissue of all infected mice. However, the largest increase in inflammatory infiltrate was observed in TcVac1_IDE/Tc mice when compared with TcVac1_IM/Tc or non-vaccinated/infected mice. The extent of tissue inflammatory infiltrate was directly associated with the control of tissue amastigote nests in vaccinated/infected (vs. non-vaccinated/infected) mice. Our results suggest that IDE delivery improves the protective efficacy of TcVac1 vaccine against T. cruzi infection in mice when compared with IM delivery of the vaccine.  相似文献   
3.
4.
5.
6.
Objectives

To find out the relative prevalence of fetal neural tube defect (NTD) and its outcome in terms of survival at birth and beyond 2 years of age.

Methods

A 10-year prospective (2008–2018) observational study was performed, which included all prenatally detected fetal NTD. Two-year follow-up was done in cases of pregnancies resulting in live birth, in terms of their survival, physical morbidity and developmental delay.

Results

NTD was seen in 401/648 (62%) cases among the central nervous system malformations. More than half of the cases (54.1%) presented after 20 weeks of gestation, and 42.8% of the mothers were primiparous. Spina bifida was seen in 206 cases, anencephaly in 144, encephalocele in 43, whereas iniencephaly was seen in only eight cases. Associated anomalies were present in 51.2%. Only 19.0% cases were live-born, and merely 11% were alive beyond 2 years of age. Among types of spina bifida, lumbosacral meningomyocele was the most common (41.6%), whereas thoracic was the rarest (8.7%). After 2 years, physical disability was observed in more than half of the cases who survived.

Conclusions

NTD is one of the commonest malformations with high mortality, and the physical and mental sub-normality is high among those who survive.

  相似文献   
7.
BackgroundThe American Radium Society (ARS) Appropriate Use Criteria brain malignancies panel systematically reviewed (PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses]) published literature on neurocognitive outcomes after stereotactic radiosurgery (SRS) for patients with multiple brain metastases (BM) to generate consensus guidelines.MethodsThe panel developed 4 key questions (KQs) to guide systematic review. From 11 614 original articles, 12 were selected. The panel developed model cases addressing KQs and potentially controversial scenarios not addressed in the systematic review (which might inform future ARS projects). Based upon quality of evidence, the panel confidentially voted on treatment options using a 9-point scale of appropriateness.ResultsThe panel agreed that SRS alone is usually appropriate for those with good performance status and 2–10 asymptomatic BM, and usually not appropriate for >20 BM. For 11–15 and 16–20 BM there was (between 2 case variants) agreement that SRS alone may be appropriate or disagreement on the appropriateness of SRS alone. There was no scenario (among 6 case variants) in which conventional whole-brain radiotherapy (WBRT) was considered usually appropriate by most panelists. There were several areas of disagreement, including: hippocampal sparing WBRT for 2–4 asymptomatic BM; WBRT for resected BM amenable to SRS; fractionated versus single-fraction SRS for resected BM, larger targets, and/or brainstem metastases; optimal treatment (WBRT, hippocampal sparing WBRT, SRS alone to all or select lesions) for patients with progressive extracranial disease, poor performance status, and no systemic options.ConclusionsFor patients with 2–10 BM, SRS alone is an appropriate treatment option for well-selected patients with good performance status. Future study is needed for those scenarios in which there was disagreement among panelists.  相似文献   
8.
9.
A 40-year-old female presented with respiratory difficulty, cough and sputum with blood streaking. Her right lung was destroyed, and trachea was shifted to the same side. On mechanical ventilation, she developed hypoxia and rise in blood pressure. Ventilator was not delivering set tidal volume. After looking into the cause, it was decided to reintubate the patient with new endotracheal tube after cutting bevel. Thereafter, there was successful ventilation.  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