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   1749篇
  免费   97篇
  国内免费   13篇
耳鼻咽喉   19篇
儿科学   53篇
妇产科学   9篇
基础医学   183篇
口腔科学   47篇
临床医学   125篇
内科学   402篇
皮肤病学   91篇
神经病学   116篇
特种医学   182篇
外国民族医学   1篇
外科学   193篇
综合类   40篇
一般理论   3篇
预防医学   122篇
眼科学   14篇
药学   112篇
中国医学   2篇
肿瘤学   145篇
  2023年   8篇
  2022年   16篇
  2021年   26篇
  2020年   18篇
  2019年   25篇
  2018年   39篇
  2017年   34篇
  2016年   34篇
  2015年   43篇
  2014年   37篇
  2013年   73篇
  2012年   77篇
  2011年   87篇
  2010年   63篇
  2009年   76篇
  2008年   69篇
  2007年   60篇
  2006年   59篇
  2005年   62篇
  2004年   72篇
  2003年   65篇
  2002年   45篇
  2001年   33篇
  2000年   34篇
  1999年   42篇
  1998年   60篇
  1997年   65篇
  1996年   60篇
  1995年   48篇
  1994年   43篇
  1993年   39篇
  1992年   17篇
  1991年   18篇
  1990年   28篇
  1989年   31篇
  1988年   29篇
  1987年   33篇
  1986年   36篇
  1985年   18篇
  1984年   11篇
  1983年   18篇
  1982年   20篇
  1981年   6篇
  1980年   15篇
  1979年   11篇
  1978年   7篇
  1977年   6篇
  1976年   12篇
  1975年   7篇
  1968年   4篇
排序方式: 共有1859条查询结果,搜索用时 593 毫秒
61.

INTRODUCTION

The Triathlon® (Stryker, Kalamazoo, MI, US) total knee replacement was designed to improve patient function and survivorship. The aim of this study was to determine whether the Triathlon® prosthesis produces better patient reported outcomes than a previous design by the same manufacturer, the Kinemax Plus.

METHODS

The outcome of 233 knees of patients with a mean age of 68 years (range: 40–80 years) who received the Kinemax Plus prosthesis were compared with the outcomes of 220 knees of patients with a mean age of 70 years (range: 42–90 years) who received the Triathlon® prosthesis. Data were collected via postal questionnaire prior to surgery as well as at 8–12 weeks and at 1 year following surgery. Validated questionnaires were used including the WOMAC® (Western Ontario and McMaster Universities) pain and function scales, the Knee injury and Osteoarthritis Outcome Score quality of life scale and the self-administered patient satisfaction scale.

RESULTS

This study found that patients who had the Triathlon® prosthesis had significantly better pain relief (p<0.0001), function (p=0.028), knee related quality of life (p<0.0001) and satisfaction (p=0.0003) at three months after surgery than those who received the Kinemax Plus prosthesis. In addition, knee related quality of life (p=0.002) and satisfaction (p=0.021) were significantly higher at one year after surgery in Triathlon® patients.

CONCLUSIONS

The findings suggest that return to function and reduction in pain may occur more quickly in patients with a Triathlon® prosthesis than in those with the Kinemax Plus.  相似文献   
62.
Purpose

The recent proliferation of minimally invasive lateral lumbar interbody fusion (LLIF) techniques has drawn attention to potential for these techniques to control or correct sagittal misalignment in adult spinal deformity. We systemically reviewed published studies related to LLIF use in adult spinal deformity treatment with emphasis on radiographic assessment of sagittal balance.

Methods

A literature review was conducted to examine studies focusing on sagittal balance restoration in adult degenerative scoliosis with the LLIF approach.

Results

Fourteen publications, 12 retrospective and 2 prospective, reported data regarding lumbar lordosis correction (1,266 levels in 476 patients) but only two measured global sagittal alignment.

Conclusion

LLIF appears to be especially effective when the lumbar lordosis and sagittal balance correction goals are less than 10° and 5 cm, respectively. However, the review demonstrated a lack of consistent reporting on sagittal balance restoration with the MIS LLIF techniques.

  相似文献   
63.
Changes in hippocampal function seem critical for cognitive impairment in Alzheimer's disease (AD). Although there is eventual loss of synapses in both AD and animal models of AD, deficits in spatial memory and inhibition of long-term potentiation (LTP) precede morphological alterations in the models, suggesting earlier biochemical changes in the disease. In the studies reported here we demonstrate that amyloid beta-peptide (Abeta) treatment of cultured hippocampal neurons leads to the inactivation of protein kinase A (PKA) and persistence of its regulatory subunit PKAIIalpha. Consistent with this, CREB phosphorylation in response to glutamate is decreased, and the decrease is reversed by rolipram, a phosphodiesterase inhibitor that raises cAMP and leads to the dissociation of the PKA catalytic and regulatory subunits. It is likely that a similar mechanism underlies Alphabeta inhibition of LTP, because rolipram and forskolin, agents that enhance the cAMP-signaling pathway, can reverse this inhibition. This reversal is blocked by H89, an inhibitor of PKA. These observations suggest that Alphabeta acts directly on the pathways involved in the formation of late LTP and agents that enhance the cAMP/PKA/CREB-signaling pathway have potential for the treatment of AD.  相似文献   
64.
65.
66.
Mohandas  N; Clark  MR; Kissinger  S; Bayer  C; Shohet  SB 《Blood》1980,56(1):125-128
Because of discrepancies between electronically and manually measured values of mean cell hemoglobin concentration (MCHC) encountered in studies of pathologic red cells, we studied the effect of cell water content on MCHC measurements by both methods. A series of red cell samples with varying water contents (54%-164% normal) were prepared from normal cells using the antibiotic nystatin. MCHC was then measured, using the microhematocrit centrifuge and three different electronic cell counters in common laboratory use. For MCHC values above 36 g/dl as measured by the spun hematocrit method, all three electronic counters under estimmated the MCHC, with increasing error as the true MCHC increased. For MCHC values below 30 g/dl, the values from two conductivity based instruments agreed with those from the spun hematocrit method, whereas one instrument based on light scattering overestimated the MCHC. These results indicate that inaccuracies in the measured mean cell volume (MCV) of dehydrated or otherwise undeformable cells may lead to spurious values for MCHC when electronic cell counters are used.  相似文献   
67.
Abdominal uterine electromyograms (uEMG) studies have focused on uterine contractions to describe the evolution of uterine activity and preterm birth (PTB) prediction. Stationary, non-contracting uEMG has not been studied. The aim of the study was to investigate the recurring patterns in stationary uEMG, their relationship with gestation age and PTB, and PTB predictivity. A public database of 300 (38 PTB) three-channel (S1–S3) uEMG recordings of 30 min, collected between 22 and 35 weeks’ gestation, was used. Motion and labour contraction-free intervals in uEMG were identified as 5-min weak-sense stationarity intervals in 268 (34 PTB) recordings. Sample entropy (SampEn), percentage recurrence (PR), percentage determinism (PD), entropy (ER), and maximum length (L MAX) of recurrence were calculated and analysed according to the time to delivery and PTB. Random time series were generated by random shuffle (RS) of actual data. Recurrence was present in actual data (p < 0.001) but not RS. In S3, PR (p < 0.005), PD (p < 0.01), ER (p < 0.005), and L MAX (p < 0.05) were higher, and SampEn lower (p < 0.005) in PTB. Recurrence indices increased (all p < 0.001) and SampEn decreased (p < 0.01) with decreasing time to delivery, suggesting increasingly regular and recurring patterns with gestation progression. All indices predicted PTB with AUC ≥0.62 (p < 0.05). Recurring patterns in stationary non-contracting uEMG were associated with time to delivery but were relatively poor predictors of PTB.  相似文献   
68.
Background: Although the advancement of the equipment and the presence of innovative techniques, percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) continues to be affected by lower procedural success in comparison with non occluded vessel PCI. Objective: We describe a new technique for the treatment of coronary CTO which utilizes a new generation of polymeric wires. Methods and Result: From March 2009 to June 2010 different strategies were adopted as “bail out” after an initial attempt failed in 117 consecutive CTO lesions. Among these, conventional strategies (CS) such as parallel wire, sub‐intimal tracking and re‐entry (STAR), microchannel technique, intracoronary ultrasound guided revascularization and anchor balloon, were used in 75 cases (64.1%), while in the remaining a new technique, the “mini‐STAR,” was used (39.9%). Although no substantial differences were observed regarding the distribution of clinical features and angiographic lesions characteristics between the populations, mini‐STAR was able to achieve a higher rate of procedural success in comparison with other CS (97.6% vs. 52%, P < 0.001) with lower contrast agent use (442 ± 259 cm3 vs. 561 ± 243 cm3, P = 0.01) and shorter procedural and fluoroscopy times (122 ± 61 vs. 157 ± 74 min, P = 0.009 and 60 ± 31 min vs. 75 ± 38 min, P = 0.03, respectively). No differences were observed in term of peri‐procedural complications such as procedural myocardial infarction, coronary perforations, and contrast‐induced nephropathy between mini‐STAR and CS. Conclusion: The mini‐STAR technique is a promising strategy for the treatment of CTO lesions, achieving a high procedural success rate and low occurrence of procedural adverse events. © 2011 Wiley Periodicals, Inc  相似文献   
69.
70.
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