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   1205篇
  免费   96篇
  国内免费   2篇
耳鼻咽喉   8篇
儿科学   49篇
妇产科学   28篇
基础医学   176篇
口腔科学   14篇
临床医学   65篇
内科学   265篇
皮肤病学   23篇
神经病学   104篇
特种医学   26篇
外科学   173篇
综合类   19篇
预防医学   111篇
眼科学   32篇
药学   94篇
肿瘤学   116篇
  2023年   12篇
  2022年   22篇
  2021年   41篇
  2020年   25篇
  2019年   34篇
  2018年   31篇
  2017年   33篇
  2016年   44篇
  2015年   33篇
  2014年   49篇
  2013年   55篇
  2012年   73篇
  2011年   77篇
  2010年   45篇
  2009年   48篇
  2008年   63篇
  2007年   69篇
  2006年   52篇
  2005年   49篇
  2004年   42篇
  2003年   44篇
  2002年   27篇
  2001年   28篇
  2000年   34篇
  1999年   27篇
  1998年   13篇
  1997年   15篇
  1996年   7篇
  1995年   5篇
  1993年   5篇
  1992年   13篇
  1991年   19篇
  1990年   15篇
  1989年   17篇
  1988年   8篇
  1987年   18篇
  1986年   9篇
  1985年   10篇
  1984年   7篇
  1983年   5篇
  1980年   5篇
  1978年   4篇
  1975年   4篇
  1974年   9篇
  1972年   3篇
  1971年   5篇
  1970年   6篇
  1969年   4篇
  1968年   4篇
  1934年   5篇
排序方式: 共有1303条查询结果,搜索用时 15 毫秒
91.
In this study we tested the possibility of seeding chondrocytes into poly (ethylene glycol)-terephthalate-poly (butylene terephthalate) PEOT/PBT scaffold through an intra-scaffold medium flow and the impact of this continuous medium flow on subsequent chondrocyte-scaffold culture. Eight cubic PEOT/PBT co-polymers (1 cm(3)) were assigned into two groups. In the semi-dynamic seeding group a continuous medium flow was created inside the scaffolds by a pump system. Around six million chondrocytes were harvested each day, suspended in 1 ml medium and delivered onto the scaffold through the perfusion for a sequential five days. Traditional chondrocytes directly seeding and static culture method was performed as control. Scanning electron microscopy (SEM) and histology assessments were performed to evaluate the distribution of chondrocytes inside the scaffolds and MTT test was chosen to check cell vitality. SEM pictures and histology slices from the perfusion group showed a better three-dimensional cell growth and extensive cell distribution inside the scaffolds; while in the control group chondrocytes only dispersedly formed a monolayer on the surface of scaffolds. Accordingly, MTT results from the perfusion group were much higher than those from control group (0.123 vs. 0.067, P<0.01). Continuous medium perfusion inside PEOT/PBT scaffold effectively combines chondrocyte seeding and culture systems for the reconstruction of tissue engineered trachea.  相似文献   
92.
93.
94.
95.
In order to understand the gene-mediated processes underlying sporadic Alzheimer's disease (AD), we carried out a subtractive cloning screen for novel AD candidate genes. We identified the gene encoding the DNA replication factor CIZ1 (CDKN1A interacting zinc finger protein 1) as being more highly expressed in Alzheimer tissue than in healthy brains. We show here that an isoform of CIZ1 which lacks a glutamine-rich region, due to alternative splicing in exon 8, is upregulated in AD brains relative to the full-length CIZ1 protein. We demonstrate for the first time that a minimal 28 amino acid sequence within this region is required for CIZ1 to associate with the nuclear matrix and to form nuclear foci.  相似文献   
96.
Increasing evidence suggests that the human brain employs multiple, interconnected brain areas for information processing and control of behavior, including the performance of laboratory tasks. Brain diseases are expected to affect these networks directly by interference and indirectly as a consequence of deficit compensation. Covariance analyses applied to functional brain imaging data open the opportunity to study neural networks and their disease-related changes in the human brain. Here, we review our analytic approach based on principal component analysis (PCA) to address such questions. We will discuss its methodological foundations and applications in patients with sensorimotor disorders. We will show that PCA in combination with, both, hypothesis-driven testing and correlation statistics provides a powerful tool for elucidating disease-related abnormalities and postlesional reorganization of neural networks in the human brain.  相似文献   
97.

Objectives

To analyse the effects of rosiglitazone administered at different times on neointimal formation in hypercholesterolemic rabbits following vascular injury.

Methods

Thirty-nine rabbits on a hypercholesterolemic diet were included. The animals underwent balloon catheter injury to the right iliac artery on day 14. They were divided into three groups as follows: control group, 13 rabbits without rosiglitazone; group I, 13 rabbits treated with rosiglitazone (3 mg/Kg body weight/day) for 28 days after the vascular injury; and group II, 13 rabbits treated with rosiglitazone (3 mg/Kg body weight/day) during all the experiment (42 days). Histological analysis was done by an experienced pathologist who was unaware of the rosiglitazone treatment. Histomorphometric parameters were performed by calculation of the luminal and intimal layer area, and intima/media layer area ratio (the area of the intimal layer divided by the area of the medial layer).

Results

Intimal area was significantly lower in group II vs. CG (p = 0.024) and group I (p = 0.006). Luminal layer area was higher in group II vs. CG (p < 0.0001) and group I (p < 0.0001). Intima/media layer area ratio was equal between CG and group I. Intima/media layer ratio area was significantly lower in group II vs. control group (p < 0.021) and group I (p < 0.003). There was a significant reduction of 65% and 71% in intima/media layer area ratio in group II vs. control group and group I, respectively.

Conclusion

Pretreatment with rosiglitazone in hypercholesterolemic rabbits submitted to vascular injury significantly reduces neointimal formation.  相似文献   
98.

Background

This case report highlights a successful steroid-free, low-dose immunosuppressive protocol for renal transplantation in a pediatric patient with Schimke immuno-osseous dysplasia with excellent 7-year patient and graft survival. Schimke immuno-osseous dysplasia is a rare multisystem disorder involving the kidney. Renal transplantation is a therapeutic option, but posttransplant mortality is high due to severe infections and posttransplant lymphoproliferative disease.

Methods

A 10-year-old girl diagnosed with Schimke immuno-osseous dysplasia and end-stage renal disease underwent an AB0-compatible living-related kidney transplantation, with no donor-specific antibodies. Our standard immunosuppression protocol was modified due to the risk of infection. Basiliximab was used as induction therapy, and a reduced dose of mycophenolate mofetil and tacrolimus was initiated following transplantation, maintaining the patient on a low tacrolimus target (3–5 μg/L). Mycophenolate mofetil was discontinued after 8 weeks due to neutropenia and the patient was kept on tacrolimus as monotherapy. Five years posttransplant the patient developed acute onset of neurological symptoms, consisting of ataxia, lack of voluntary coordination, balance, aphasia and dysphagia, and diplopia. She recovered without neurological deficits within 6 weeks. Extensive evaluation revealed no pathology. To avoid a possible a component of tacrolimus-induced cerebral vasoconstriction, the immunosuppressive therapy was changed to everolimus.

Results

Seven years posttransplant, the patient has experienced no serious infections, no rejections, and had excellent graft function, and no de novo donor-specific antibodies.

Conclusions

The present results indicate that low-dose immunosuppressive therapy after renal transplantation with low immunological risk should be considered for patients with Schimke immuno-osseous dysplasia.  相似文献   
99.
To investigate whether hemoglobin, white blood cell count (WBC), urea, sodium, albumin, and C-reactive protein at discharge in patients hospitalized for community-acquired pneumonia (CAP) are associated with 30-day readmission. This study is a retrospective cohort study, which included all adult patients discharged after hospitalization for CAP from three Danish hospitals between January 2011 and July 2012. The outcome was all-cause, unplanned, 30-day readmission. Biomarker concentrations at discharge were transformed into binary variables by using either upper or lower quartiles as cut-off; the upper quartile was used for WBC, urea, and C-reactive protein, and the lower quartile was used for hemoglobin, sodium, and albumin. The study population consisted of 1149 patients. One hundred eighty-four (16.0%) patients were readmitted. Independent risk factors of readmission were WBC?≥?10.6 cells?×?109/L (hazard ratio 1.50; 95% CI, 1.07–2.11) and albumin <32 g/L (hazard ratio 1.78; 95% CI, 1.24–2.54) at discharge and the presence of ≥?2 co-morbidities (hazard ratio 1.74; 95% CI, 1.15–2.64). When WBC, albumin, and co-morbidities were combined into a risk-stratification tool, there was a step-wise increase in risk of readmission for patients with 1, 2, or 3 risk factors with hazard ratios of 1.76 (95% CI, 1.25–2.49), 2.59 (95% CI, 1.71–3.93), and 6.15 (95% CI 3.33–11.38), respectively. WBC?≥?10.6 cells?×?109/L and albumin <?32 g/L at discharge and the presence of ≥?2 co-morbidities were independently associated with increased risk of 30-day readmission.  相似文献   
100.
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