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   4475篇
  免费   25篇
  国内免费   44篇
耳鼻咽喉   49篇
儿科学   1053篇
妇产科学   30篇
基础医学   347篇
口腔科学   20篇
临床医学   372篇
内科学   701篇
皮肤病学   19篇
神经病学   173篇
特种医学   174篇
外科学   598篇
综合类   106篇
预防医学   331篇
眼科学   44篇
药学   184篇
中国医学   20篇
肿瘤学   323篇
  2019年   88篇
  2018年   181篇
  2017年   176篇
  2016年   177篇
  2015年   46篇
  2014年   71篇
  2013年   73篇
  2012年   219篇
  2011年   1863篇
  2010年   718篇
  2009年   306篇
  2008年   132篇
  2007年   48篇
  2006年   18篇
  2005年   10篇
  2004年   9篇
  2003年   10篇
  1999年   8篇
  1998年   33篇
  1997年   26篇
  1996年   43篇
  1995年   45篇
  1994年   44篇
  1993年   23篇
  1992年   12篇
  1991年   5篇
  1989年   3篇
  1985年   3篇
  1983年   5篇
  1982年   5篇
  1981年   6篇
  1980年   8篇
  1978年   3篇
  1977年   5篇
  1976年   3篇
  1975年   13篇
  1973年   7篇
  1970年   3篇
  1965年   4篇
  1964年   12篇
  1963年   4篇
  1962年   5篇
  1961年   12篇
  1960年   5篇
  1959年   7篇
  1958年   4篇
  1921年   2篇
  1914年   2篇
  1911年   2篇
  1908年   3篇
排序方式: 共有4544条查询结果,搜索用时 0 毫秒
41.
??Abstract?? Objective Toinvestigatethe correlation among exhalednitric oxide??lung function and Asthma Control Test inasthmatic childrenand the clinicalsignificance. Methods A total of 136 cases of asthmatic children aged 5 to 15 years old were recruited from Shengjing Hospital of China Medical University.The fraction of exhaled nitric oxide?? lung function and ACTscore were measured??and the correlation among them was analyzed. Results Negative correlation was found between FeNOand ACT??r= -0.251??P<0.005??.Negative correlation was found between FeNOandFEV1/FVC of lung function??r=-0.206??P<0.05????but not FEV1or PEF.Positive correlation was found betweenACT scoreandFEV1/FVC of lung function ??r=0.242??P<0.01???? but not FEV1or PEF. Conclusion For all subjects??FeNO is negatively correlated with ACT score and FEV1/FVC.ACT is positively correlated with FEV1/FVC.When the subjects are grouped??the three don’t have stable correlations.FeNO is a good biomarker to evaluate the airway inflammation of asthmatic children.ACT score evaluates the level of asthma control in children.Lung function evaluates airway obstruction.FeNO??lung function andACTare different measurements that evaluate asthma in different ways.None of them can be used instead of another in clinical practice??and they are complementary.Combinedapplicationscan effectivelyimprove the diagnosis??treatment and asthmacontrol inasthmatic children.  相似文献   
42.
??Abstract??Allogeneic hematopoietic stem cell transplantation ??HSCT?? is the only curative therapy for severe beta-thalassemia major. Patients with an available human leukocyte antigen ??HLA?? identical sibling donor should be offered HSCT as soon as possible before development of iron overload and transfusion associated complications?? and the cure rate was up to 80%??90%. High-resolution HLA typing matched unrelated donor transplants also achieved good results. HSCT from HLA-mismatched relatives or HLA-phenotypically-identical donor is an option to be performed in expert centers. Optimization of conditioning regimen and techniques to control transplant-related complications will further improve outcomes.  相似文献   
43.
??Abstract??Congenital hemolytic anemia ??CHA?? is a hereditary disorder with main clinical presentation of hemolytic anemia??It is the most common disease of hereditary disorders in the world. According to the pathogenic mechanism??the disorders can be divided into three groups??abnormalities of the red cell membrane??red cell enzyme disorders and hemoglobinopathies.The most common CHA are hereditary spherocytosis??G-6-PD deficiency and the thalassemias??This article focuses on the management of these three types of diseases.  相似文献   
44.
??Abstract?? Objective To analyze ALDH3A2 mutation in four Chinese patients with Sjögren-Larsson syndrome ??SLS??. Methods Four patients were clinically diagnosed with SLS. Respectively take 3 ml of peripheral blood. All 11 exons and exon-intron boundaries of ALDH3A2 gene were amplified by polymerase chain reaction ??PCR?? and directly sequenced for genomic DNA. Results 1. All four patients had congenital ichthyosis?? mental retardation??and spastic diplegia or tetraplegia. Patient 1 had a compound heterozygote??c.1157A??G inherited from her father?? IVS5-1del G inherited from her mother. Both her parents had normal phenotype. Patient 2 and Patient 3 were siblings?? they were both homozygotes??a A-to-G transition at nucleotide 1157 in exon 8. The heterozygosity was demonstrated in their mother. Both her parents had normal phenotype. Conclusion Two different mutations were examined in these 4 Chinese patients?? and the SLS cases were confirmed by ALDH3A2 mutation analysis.  相似文献   
45.
??Abstract?? Objective To identify the clinical features and the prognosis of anti-NMDAR encephalitis in children??so as to improve the pediatrician’s awareness about this disease. Methods The clinical features??therapeutic regimen and prognosis of 17 children with anti-NMDAR encephalitis were summarized by a retrospective and follow-up study. Results Among the 17 patients with anti-NMDAR encephalitis??12 were males and 5 were females.Their age varied from 2 to 12 years??and the average age was 5 years 8 months.The most common initial symptoms were convulsions ??7 cases?? and psychiatric symptoms ??7 cases??.The common symptoms in the course of the disease were psychiatric symptoms??17 cases????sleep disorders ??16 cases????extrapyramidal symptoms ??14 cases????and convulsion ??11 cases??.Only 4 patients had autonomic symptoms.The anti-NMDAR antibody were found in all the patients’CSF.The EEG test of 16 patients showed diffused slow background.Tumors were not found in any patient. Fourteen cases were treated with IVIg and methylprednisolone??2 cases only received IVIg therapy and 1 case gave up.Rituximab ??2 cases?? and cyclophosphamide ??1 cases?? were administrated in 3 cases with no improvement after the above treatment.The patients had been followed up for 3 to 15 months.Twelve of them recovered completely??2 cases died??2 cases had epilepsy??and 1 case had speech disorder. Conclusion Psychiatric symptoms??sleep disorders??extrapyramidal symptoms and convulsion are the common symptoms of anti-NMDAR encephalitis in children.Tumors and autonomic nervous system dysfunction rarely happen. Immunotherapy is effective in the majority of the patients.The prognosis of anti-NMDAR encephalitis in children is optimistic.  相似文献   
46.
This study aimed to analyze the role of endothelial progenitor cell (EPC)-derived angiogenic factors and chemokines in the multistep process driving angiogenesis with a focus on the recently discovered macrophage migration inhibitory factor (MIF)/chemokine receptor axis. Primary murine and murine embryonic EPCs (eEPCs) were analyzed for the expression of angiogenic/chemokines and components of the MIF/CXC chemokine receptor axis, focusing on the influence of hypoxic versus normoxic stimulation. Hypoxia induced an upregulation of CXCR2 and CXCR4 but not CD74 on EPCs and triggered the secretion of CXCL12, CXCL1, MIF, and vascular endothelial growth factor (VEGF). These factors stimulated the transmigration activity and adhesive capacity of EPCs, with MIF and VEGF exhibiting the strongest effects under hypoxia. MIF-, VEGF-, CXCL12-, and CXCL1-stimulated EPCs enhanced tube formation, with MIF and VEGF exhibiting again the strongest effect following hypoxia. Tube formation following in vivo implantation utilizing angiogenic factor-loaded Matrigel plugs was only promoted by VEGF. Coloading of plugs with eEPCs led to enhanced tube formation only by CXCL12, whereas MIF was the only factor which induced differentiation towards an endothelial and smooth muscle cell (SMC) phenotype, indicating an angiogenic and differentiation capacity in vivo. Surprisingly, CXCL12, a chemoattractant for smooth muscle progenitor cells, inhibited SMC differentiation. We have identified a role for EPC-derived proangiogenic MIF, VEGF and MIF receptors in EPC recruitment following hypoxia, EPC differentiation and subsequent tube and vessel formation, whereas CXCL12, a mediator of early EPC recruitment, does not contribute to the remodeling process. By discerning the contributions of key angiogenic chemokines and EPCs, these findings offer valuable mechanistic insight into mouse models of angiogenesis and help to define the intricate interplay between EPC-derived angiogenic cargo factors, EPCs, and the angiogenic target tissue.  相似文献   
47.
48.

Goal of work  

While significance of the concept of meaning in understanding adaptation to cancer is widely accepted, it has been little studied, especially in longitudinal data. This study aims to clarify the role of global meaning and meaning-related life attitudes (death acceptance and goal seeking) in predicting different aspects of psychological and existential distress by reference to a specified research model.  相似文献   
49.

Objectives

To define the potential, limitations and synergies of micro-CT and other non-radiological techniques for the quantification of emphysema and related processes in mice, by performing a complete characterization of the elastase-induced emphysema model.

Materials and methods

Ninety A/J mice (45 treated and 45 controls) were studied at different time points using breath-hold gated micro-CT, functional test parameters, RT-PCR for RNA cytokine expression, Luminex technology for cytokine plasma concentration and histomorphometry.

Results

Both histomorphometry and micro-CT imaging reflect rapid initial emphysema progression followed by steady-state development at decreasing rates. Cytokine measurements reveal an acute inflammatory response within the first 24?h that disappears after the first week. Limited systemic effect was observed based on plasma cytokine concentration. Lung compliance decreases during the acute inflammation phase and increases afterwards.

Conclusion

Histomorphometry is the most sensitive technique since it detects airspace enlargement before the other methods (1?h after treatment). Micro-CT correlates well with histology (r2?=?0.63) proving appropriate for longitudinal studies. Functional test parameters do not necessarily correlate with the extent of emphysema, as they can be influenced by acute inflammation. Finally, cytokine measurements correlate with the presence of inflammation in histology but not with emphysema.  相似文献   
50.

Background  

Pancreatic neuroendocrine tumors (PNETs) are a characteristic feature of the tumor syndromes multiple endocrine neoplasia type 1 (MEN-1) and von Hippel-Lindau disease (VHL). With VHL, about 10% of the patients exhibit PNETs by age 40 years. Metastatic potential is high if the tumors have grown to >3 cm in diameter. Optimal surgical treatment is still a challenge.  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