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   4586篇
  免费   257篇
  国内免费   23篇
耳鼻咽喉   55篇
儿科学   153篇
妇产科学   49篇
基础医学   619篇
口腔科学   100篇
临床医学   331篇
内科学   1039篇
皮肤病学   217篇
神经病学   292篇
特种医学   118篇
外科学   528篇
综合类   39篇
预防医学   213篇
眼科学   186篇
药学   336篇
  2篇
中国医学   19篇
肿瘤学   570篇
  2024年   13篇
  2023年   57篇
  2022年   90篇
  2021年   147篇
  2020年   70篇
  2019年   100篇
  2018年   163篇
  2017年   117篇
  2016年   117篇
  2015年   109篇
  2014年   165篇
  2013年   175篇
  2012年   329篇
  2011年   319篇
  2010年   219篇
  2009年   174篇
  2008年   255篇
  2007年   277篇
  2006年   294篇
  2005年   248篇
  2004年   238篇
  2003年   231篇
  2002年   223篇
  2001年   64篇
  2000年   75篇
  1999年   82篇
  1998年   42篇
  1997年   39篇
  1996年   30篇
  1995年   30篇
  1994年   23篇
  1993年   14篇
  1992年   32篇
  1991年   36篇
  1990年   26篇
  1989年   36篇
  1988年   33篇
  1987年   29篇
  1986年   25篇
  1985年   29篇
  1984年   14篇
  1983年   13篇
  1982年   13篇
  1981年   4篇
  1980年   6篇
  1979年   7篇
  1974年   2篇
  1968年   6篇
  1967年   4篇
  1966年   7篇
排序方式: 共有4866条查询结果,搜索用时 15 毫秒
61.
Green PH  Barry M  Matsutani M 《Gastroenterology》2003,124(2):585-6; author reply 586
  相似文献   
62.
63.
An examination of the change in plasma concentration of OH-flutamide in low-dose flutamide (250 mg/day) monotherapy for 5 prostate cancer patients was performed. We treated 5 patients diagnosed with prostate cancer between September and November 2002. The plasma concentrations of OH-flutamide, PSA and AST/ALT were measured before and after low-dose flutamide monotherapy was started. The plasma concentrations of OH-flutamide were stable in the third day after medication was started, and even when compared with the plasma concentrations of OH-flutamide 375 mg/day, there was no significant difference. Although at the observation period was short, PSA fell favorably in all patients. The AST/ALT were in the normal range in all patients. The low-does flutamide therapy has been one of medical treatments if its safety and effectiveness has been demonstrated.  相似文献   
64.
Kawakami M  Kawakami K  Takahashi S  Abe M  Puri RK 《Cancer》2004,101(5):1036-1042
BACKGROUND: Compared with normal brain tissue cells, human malignant glioma cells express higher levels of interleukin-13 receptor (IL-13R). However, whether this receptor is expressed in situ has not been carefully examined. With IL-13R-targeted cytotoxin (IL13-PE38QQR, comprising IL-13 and a mutated form of Pseudomonas exotoxin [PE]) being tested in three Phase I/II clinical trials for the treatment of adult human glioma, and with pediatric studies being planned, the authors set out to analyze pediatric brain tumor tissue specimens for the expression of IL-13R. METHODS: Using in situ hybridization and immunohistochemical staining, the authors examined 58 pediatric brain tumor specimens for expression of the predominant IL-13 binding and internalizing protein (IL-13Ralpha2) chain at the mRNA and protein levels. RESULTS: Overall, approximately 83% of pediatric brain tumor samples expressed IL-13Ralpha2. One hundred percent (11 of 11) high-grade astrocytoma, 79% (26 of 33) low-grade astrocytoma, 67% (4 of 6) medulloblastoma, and 67% (2 of 3) ependymoma samples were positive for IL-13Ralpha2. Among IL-13Ralpha2-positive samples, 88% (42 of 48 samples) had positive expression in > or = 50% of all tumor fields. The results obtained using both assays were consistent with each other. CONCLUSIONS: The current study established that pediatric brain tumor specimens expressed the IL-13Ralpha2 chain. Because the IL-13Ralpha2 chain is a major binding component of the IL-13R complex, these results suggest that the targeting of IL-13R may represent a useful approach for the treatment of pediatric brain tumors.  相似文献   
65.
The production of interferon-beta by NB1-RGB fibroblast cells cultured on protein and peptide membranes prepared from silk fibroin, motif peptides of silk fibroin [(AG)(n)] containing arginine-glycine-aspartic acid (RGD) peptide, and Pronectin was investigated. The cell density on various protein and peptide membranes was approximately the same, although the production of interferon-beta depended significantly on the membranes where the cells were cultured. The highest production of interferon-beta was observed when the cells were cultured on (AG)(6)RGD(AG)(7) membranes prepared with hexafluoroacetone (HFA) as the casting solvent. On RGD-containing peptide membranes more centrally located in the peptides, the cells produced more interferon-beta when the peptide membranes were prepared with HFA as the casting solvent. However, there was no enhanced production of interferon-beta by cells on (AG)(6)RGD(AG)(7) membranes prepared with 9 mol/L LiBr or 4.5 mol/L LiClO(4) solution as the casting solvent. Therefore, both the chemical composition and the secondary and higher order structure of the peptide membranes are important for enhanced production of interferon-beta. The blocking of integrin beta(1) on the cells by anti-integrin beta(1) antibody prevented the enhanced production of interferon-beta on (AG)(6)RGD(AG)(7) membranes prepared with HFA. We suggest that the cells must bind to the RGD sequence having the appropriate conformation through their integrin beta(1) for enhanced production of interferon-beta.  相似文献   
66.
Accumulating evidence suggests that among the 3 human apolipoprotein E (apoE) isoforms encoded by the human APOE gene, the e4 allele may act to exacerbate brain damage in humans and animals. This study aimed to compare the isoform-specific vulnerability conferred by human apoE to ischemic brain damage, using mice expressing human apoE isoforms (apoE2, apoE3, or apoE4) in place of mouse apoE, produced by the gene-targeting technique in embryonic stem cells (knock-in, KI). Homozygous human apoE2 (2/2), apoE3 (3/3), or apoE4 (4/4) KI mice were subjected to permanent focal cerebral ischemia by a modified intraluminal suture method. Twenty-four h thereafter, brain damage, (as estimated by infarct volume and neurologic deficit) was significantly worse in 4/4 KI mice versus 2/2 or 3/3 KI mice (p < 0.001 for each comparison), with no significant differences between 2/2 and 3/3 KI mice. Immunohistochemistry for human apoE expression revealed similar apoE distribution with no significant difference in the immunostaining intensity among the 3 lines of KI mice. Notably. increased expression of human apoE was detected in neurons and astrocytes in the peri-infarct area, and a punctate expression pattern was evident in the border between the infarct and peri-infarct areas in all KI mice subjected to ischemia. Taken together, our results show that apoE affects the outcome of acute brain damage in an isoform-specific fashion (apoE4 > apoE3 = apoE2) in genetically engineered mice.  相似文献   
67.
We report three patients with sporadic merosin-positive congenital muscular dystrophy (CMD) with torticollis and/or developmental dislocation of the hip in early childhood. Diagnosis of merosin-positive CMD was based on their clinical and dystrophic muscle biopsy findings. At the age 13 months, patient 1 was found to have developmental dislocation of both hips, which was surgically treated at 5 years. Patient 2 had severe torticollis and contracture of both hip joints which had been present since the neonatal period, and underwent repair of the torticollis at 2 years. Patient 3 was found to have developmental dislocation of the left hip at one month of age. Although she had generalized muscle hypotonia she learned to walk at 23 months. She had no facial muscle involvement nor contracture of joints, but had hyperlaxity of distal joints. Her muscle biopsy showed complete collagen VI deficiency immunohistochemically. In contrast to merosin-deficient CMD, merosin-positive CMD appears to be a group of heterogeneous diseases. Since collagen VI was reported to be defective in Ullrich's disease, patient 3 may be diagnosed as having Ullrich's disease but had no typical clinical characteristics of the disease. Further study is needed to identify the pathogenetic mechanism of congenital muscular dystrophy with early joint abnormalities to determine whether there is a primary abnormality of the connective tissue including collagen VI.  相似文献   
68.
69.
Psychological distress in 248 evacuees from a volcanic eruption was evaluated using a 30-item General Health Questionnaire (GHQ-30) at four time points after evacuation: 6 months, 12 months, 24 months and 44 months. The proportion of evacuees with psychological distress (defined as a GHQ score >/= 8) significantly decreased from 66.1% (6 months) to 45.6% (44 months). The GHQ mean score significantly improved from 12.6 to 8.9. Investigation of each factor on the GHQ showed progressive improvement over time in 'anxiety, tension and insomnia' and 'anergia and social dysfunction'. However, 'depression' began to improve only after 44 months and 'interpersonal dysfunction' started to worsen after 12 months. The dysfunction in interpersonal relationships continued at 44 months. Examination of the relation between GHQ mean scores and age group showed that recovery from psychological distress was more difficult in middle-aged and older evacuees than in younger evacuees.  相似文献   
70.
In acute-phase Kawasaki disease, neutrophils cause injury to the coronary arterial endothelium through the production of elastase. Previous research has demonstrated the modulation of neutrophil function and kinetics, such as development and maturation, by granulocyte colony-stimulating factor (G-CSF). To examine the correlation between G-CSF and cardiac complications in Kawasaki disease, functional activity of serum G-CSF and cytokines was measured by enzyme-linked immunosorbent assay in 30 patients with acute-phase Kawasaki disease aged 2 months to 5 years. The mean serum G-CSF was higher in the 1st week of Kawasaki disease than during weeks 2 to 4, and G-CSF was significantly higher in patients with coronary artery dilatation (CAL) than in those without. There was no significant difference in the activity of other cytokines studied or white blood cell counts between the patients with CAL. Conclusion: granulocyte colony-stimulating factor is correlated with coronary artery dilatation in acute-phase Kawasaki disease and increased neutrophil function may contribute to the pathogenesis of coronary arterial endothelial injury in these patients.  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