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   3132篇
  免费   104篇
  国内免费   20篇
耳鼻咽喉   23篇
儿科学   37篇
妇产科学   49篇
基础医学   425篇
口腔科学   48篇
临床医学   324篇
内科学   682篇
皮肤病学   16篇
神经病学   353篇
特种医学   90篇
外科学   522篇
综合类   5篇
一般理论   1篇
预防医学   176篇
眼科学   23篇
药学   255篇
中国医学   2篇
肿瘤学   225篇
  2023年   13篇
  2022年   25篇
  2021年   58篇
  2020年   25篇
  2019年   41篇
  2018年   71篇
  2017年   26篇
  2016年   45篇
  2015年   62篇
  2014年   97篇
  2013年   163篇
  2012年   216篇
  2011年   249篇
  2010年   113篇
  2009年   121篇
  2008年   238篇
  2007年   242篇
  2006年   239篇
  2005年   216篇
  2004年   218篇
  2003年   206篇
  2002年   225篇
  2001年   32篇
  2000年   33篇
  1999年   33篇
  1998年   48篇
  1997年   44篇
  1996年   22篇
  1995年   20篇
  1994年   22篇
  1993年   13篇
  1992年   14篇
  1991年   7篇
  1990年   7篇
  1989年   7篇
  1988年   4篇
  1987年   3篇
  1986年   6篇
  1985年   2篇
  1984年   6篇
  1983年   7篇
  1981年   3篇
  1980年   4篇
  1979年   2篇
  1976年   1篇
  1970年   1篇
  1964年   1篇
  1963年   1篇
  1961年   1篇
  1959年   2篇
排序方式: 共有3256条查询结果,搜索用时 15 毫秒
991.

Purpose

Cervical spine alignment interests appeared recently and relationships between the pelvis and the cervical spine have been reported but remain unclear. In this study, postoperative changes for cranial, cervical, lumbar and sagittal balance parameters have been measured in adult scoliosis surgery without major sagittal malalignment to appreciate the adaptation of the cervical spine.

Methods

Twenty-nine consecutive patients with a surgical adult degenerative scoliosis treated with a T8–T11 to iliac fusion without PSO or multiple Ponte’s osteotomies had preoperative and postoperative full spine EOS radiographies to measure spino-pelvic parameters. Correlation analysis between the different parameters was performed.

Results

Lower cervical, lordosis, lumbar lordosis and thoracic kyphosis were increased in postoperative as no changes were observed for upper cervical lordosis. C1–C7 CL highly correlated (0.85 in preoperative and 0.87 in postoperative) with C7 slope, which highly correlated itself with global balance parameters (0.74 in preoperative and 0.71 in postoperative for CAM-PL) underlining the relationship between cervical spine alignment and global malalignment.

Conclusions

Modifications of lower CL are observed, as upper CL remains constant. If no correlation was found for LL, TK and CL changes, CL appears to be highly correlated with C7 slope, which highly correlated itself with sagittal global balance parameters. C7 slope appears as a base for CL influenced by the spine global alignment.
  相似文献   
992.
European Spine Journal -  相似文献   
993.

Introduction

Some researchers have suggested that the weight loss of a patient who has undergone bariatric surgery could be influenced by his or her family environment. Indeed, some people decide to undergo surgery after another family member has had the operation. This study aimed to evaluate the results of longitudinal sleeve gastrectomy (LSG) performed for several members of a family compared with to a control group of unrelated individuals.

Material and methods

On the basis of preoperative data, 78 LSG patients from 39 families (the LSG-family group) were matched 1:1 with 78 LSG patients selected from among 550 LSG patients whose family members had undergone no bariatric surgery (the LSG group). Within the LSG-family group, a distinction was drawn between family members who had undergone surgery before their relation (the LSG-family 1 subgroup) and those who had undergone surgery after their relation (the LSG-family 2 subgroup).

Results

The median preoperative body mass index (BMI) in each of the two groups was 48.1 kg/m². The LSG-family and LSG groups 24 months after surgery had respective mean BMIs of 28.6 and 32.5 kg/m² (p ≤ 0.01), excess weight losses (EWLs) of 83.5 % and 71.4 % (p ≤ 0.01), and missed consultation rates of 13.1 % and 25.9 % (p = 0.04). A comparison of the LSG-family 1 and family 2 subgroups 24 months after surgery showed respective mean BMIs of 30.0 and 27.5 kg/m² (p = 0.12), EWLs of 80.2 % and 86.2 % (p = 0.32), and missed consultation rates of 14.1 % and 12.1 % (p = 0.22).

Conclusion

The outcome for LSG in terms of weight loss and postoperative follow-up care was better in the family group than in the control group. This may have been due to better postoperative follow-up care for the patients in the LSG-family group. Within a family, the patients who had surgery after their relation showed a trend toward greater weight loss and better postoperative follow-up care.  相似文献   
994.
We combined in vitro intracellular recording from prefrontal cortical neurons with simulated synaptic activity of a layer 5 prefrontal microcircuit using a dynamic clamp. During simulated in vivo background conditions, the cell responded to a brief depolarization with a sequence of spikes that outlasted the depolarization, mimicking the activity of a cell recorded during the delay period of a working memory task in the behaving monkey. The onset of sustained activity depended on the number of action potentials elicited by the cue-like depolarization. Too few spikes failed to provide enough NMDA drive to elicit sustained reverberations; too many spikes activated a slow intrinsic hyperpolarization current that prevented spiking; an intermediate number of spikes produced sustained activity. When high dopamine levels were simulated by depolarizing the cell and by increasing the amount of NMDA current, the cell exhibited spontaneous 'up-states' that terminated by the activation of a slow intrinsic hyperpolarizing current. The firing rate during the delay period could be effectively modulated by the standard deviation of the inhibitory background synaptic noise without significant changes in the background firing rate before cue onset. These results suggest that the balance between fast feedback inhibition and slower AMPA and NMDA feedback excitation is critical in initiating persistent activity and that the maintenance of persistent activity may be regulated by the amount of correlated background inhibition.  相似文献   
995.
OBJECTIVE Partial androgen Insensitivity syndromes are the cause of genital ambiguity that is at times quite severe; there is, therefore, a high demand for prenatal diagnosis in families already afflicted with this syndrome. When the mutation has not been identified, the diagnosis can be made by the study of the polymorphisms of the androgen receptor gene. To perform molecular prenatal diagnosis in a family with partial androgen insensitivity syndrome, we studied the Hind III polymorphism of the androgen receptor gene on the trophoblastic DNA. The use of this restriction fragment length polymorphism tracked maternal X chromosome segregation and established prenatal diagnosis although the mutation had not yet been identified in this family. FAMILY The mother had been previously described as heterozygous for the Hind III polymorphism and chromosomal segregation analysis showed that the affected allele was associated with the 6.7-kb Hind III fragment. MEASUREMENTS Hind III RFLP with an androgen receptor gene cDNA probe was realized on the trophoblastic DNA, along with measurement of androgen binding activity on the trophoblastic cells. RESULTS We detected the presence of the 6.7-kb fragment In the DNA of the trophoblastic cells suggesting the fetus was affected. Partial androgen insensitivity syndrome was confirmed by a considerable decrease in androgen binding activity on the trophoblastic cells and by sonography of the fetus. After a therapeutic abortion requested by the parents, the diagnosis was confirmed by clinical examination of the fetus, biochemical analyses of the fetal androgen receptor, and molecular studies of the fetal DNA. CONCLUSIONS When the mutation of the androgen receptor gene has not been identified, Hind III polymorphism of the trophoblastic DNA is useful in the prenatal diagnosis of androgen insensitivity syndrome in high-risk families.  相似文献   
996.
We describe the first case of spontaneous splenic rupture associated with tinzaparin in a cancer patient. This low-molecular-weight heparin was administrated for deep venous thrombosis and pulmonary embolism. No underlying splenic pathology predisposing to this condition was found.  相似文献   
997.
Two multi-component scores (Fibrotest and Actitest) have been proposed to evaluate liver fibrosis or necro-inflammatory lesions as an alternative to liver biopsy. This approach requires standardization of alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) determinations. For this purpose, ALT and GGT values were assigned to a multi-enzyme material using the appropriate primary reference procedure. This material was used as a common calibrator for sera from 20 patients with viral hepatitis. Measurements were carried out in 11 laboratories, using their own automated routine methods and compared to results obtained using the primary reference procedure. The expression of results in multiples of the upper reference limit worsened the inter-laboratory variation for both enzymes. The multi-enzyme material was commutable for ALT and GGT determination carried out with six analytical systems. Common calibration significantly improved inter-laboratory consistency, which finally reached 1.8% and 3.3% for ALT and GGT, respectively. For each enzyme, it also permitted the retention of a common reference interval for a set of calibrated methods and the improvement of inter-laboratory coherency of Fibrotest and Actitest scores.  相似文献   
998.
999.
Tuberculosis presenting as acute hepatitis in a renal transplant recipient   总被引:1,自引:0,他引:1  
We observed a kidney transplant recipient in whom acute hepatitis was the initial manifestation of tuberculosis, preceding radiological lung involvement by several weeks. The diagnosis was suspected and treatment initiated based on the finding of a granulomatous hepatitis on liver biopsy. Mycobacterial, tuberulosis was grown and identified first in liver samples and only later in sputum and bone marrow. This case illustrates the protean manifestations of tuberculosis in immunosuppressed patients.  相似文献   
1000.
The expression of mitochondrial proteins of two patients suffering from myopathy with progressive exercise intolerance and exhibiting a deficiency in the enzymatic activity of complex III (ubiquinol-cytochrome c reductase) has been analyzed by immunological titration. In both patients, the Fe-S protein, the cytochrome b and the 9.5 kDa protein were decreased while the expression of the other complex III subunits were close to normal values. This data indicates that, in some mitochondrial myopathies, proteins of the respiratory chain complexes can be accumulated in mitochondria without being integrated into a functional complex. This may be explained either by a lack of control of the coordination between the synthesis of subunits of mitochondrial and nuclear origin or by a difference in the degradation rate of the various subunits which are not properly assembled.  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