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   12996篇
  免费   621篇
  国内免费   68篇
耳鼻咽喉   92篇
儿科学   217篇
妇产科学   146篇
基础医学   1804篇
口腔科学   238篇
临床医学   817篇
内科学   3316篇
皮肤病学   193篇
神经病学   1101篇
特种医学   729篇
外科学   1817篇
综合类   34篇
预防医学   426篇
眼科学   163篇
药学   1083篇
中国医学   33篇
肿瘤学   1476篇
  2023年   67篇
  2022年   103篇
  2021年   191篇
  2020年   106篇
  2019年   109篇
  2018年   148篇
  2017年   121篇
  2016年   183篇
  2015年   206篇
  2014年   230篇
  2013年   291篇
  2012年   514篇
  2011年   553篇
  2010年   343篇
  2009年   284篇
  2008年   523篇
  2007年   597篇
  2006年   597篇
  2005年   605篇
  2004年   644篇
  2003年   641篇
  2002年   728篇
  2001年   519篇
  2000年   531篇
  1999年   474篇
  1998年   224篇
  1997年   171篇
  1996年   187篇
  1995年   160篇
  1994年   115篇
  1993年   106篇
  1992年   402篇
  1991年   331篇
  1990年   299篇
  1989年   358篇
  1988年   285篇
  1987年   295篇
  1986年   234篇
  1985年   197篇
  1984年   169篇
  1983年   111篇
  1982年   86篇
  1981年   74篇
  1980年   67篇
  1979年   108篇
  1978年   74篇
  1977年   67篇
  1976年   43篇
  1975年   32篇
  1974年   21篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
61.
62.
63.
Objective. High levels of interleukin-6 (IL-6) have been found in the synovial fluid of patients with rheumatoid arthritis (RA). We undertook the present study to investigate the role of IL-6 in this disease. Methods. We examined the effects of IL-6, in comparison with IL-1, on the biosynthesis of extracellular matrix macromolecules and of matrix-degrading proteinases in rheumatoid synovial fibroblasts. Results. In rheumatoid synovial fibroblasts, IL-6 by itself enhanced the production of plasminogen activator, its inhibitor, and tissue inhibitor of metalloproteinases, whereas it did not modulate the biosynthesis of precursor of matrix metalloproteinase 1 (proMMP-1) (tissue collagenase), proMMP-3 (stromelysin), or connective tissue components. However, IL-1–induced production of proMMP-1 and proMMP-3 was preferentially augmented by IL-6. Conclusion. These results suggest that in RA, IL-6 may participate along with IL-1 in fine tuning of the catabolism of connective tissue components, by modulating the balance between connective tissue–degrading enzymes and their inhibitors.  相似文献   
64.
European Archives of Oto-Rhino-Laryngology - We morphometrically analyzed human facial muscles, and evaluated the Yanagihara facial nerve grading system using our data. We used 15 types of human...  相似文献   
65.
A 46-year-old woman developed takotsubo cardiomyopathy and nephrotic syndrome. The first kidney biopsy suggested non-immune-complex-mediated membranoproliferative glomerulonephritis (MPGN), and she was diagnosed with glomerular endothelial injury associated with takotsubo cardiomyopathy. A second biopsy was performed two years later because of persistent proteinuria despite renin-angiotensin system inhibition. This biopsy indicated non-immune-complex-mediated MPGN, but a mesangial and subendothelial substance of a higher electron density than that in the first biopsy was detected, suggesting the possibility of glomerular disease with non-immune deposits rather than endothelial injury. Finally, she was diagnosed with fibronectin nephropathy. Although rare, fibronectin glomerulopathy should be considered in non-immune-complex-mediated MPGN.  相似文献   
66.
67.
Aims/IntroductionWe aimed to replicate a new diabetes subclassification based on objective clinical information at admission in a diabetes educational inpatient program. We also assessed the educational outcomes for each cluster.MethodsWe included diabetes patients who participated in the educational inpatient program during 2009–2020 and had sufficient clinical information for the cluster analysis. We applied a data‐driven clustering method proposed in a previous study and further evaluated the clinical characteristics of each cluster. We investigated the association between the clusters and changes in hemoglobin A1c level from the start of the education program. We also assessed the risk of re‐admission for the educational program.ResultsWe divided a total of 651 patients into five clusters. Their clinical characteristics followed the same pattern as in previous studies. The intercluster ranking of the cluster center coordinates showed strong correlation coefficients with those of the previous studies (mean ρ = 0.88). Patients classified as severe insulin‐resistant diabetes (cluster 3) showed a more pronounced progression of renal dysfunction than patients classified as the other clusters. The patients classified as severe insulin‐deficient diabetes (cluster 2) had the highest rate of reduction in hemoglobin A1c level from the start of the program (P < 0.01) and a tendency toward a lower risk of re‐admission for the education program (hazard ratio 0.47, P = 0.09).ConclusionWe successfully replicated the diabetes subclassification using objective clinical information at admission for the education program. In addition, we showed that severe insulin‐deficient diabetes patients tended to have better educational outcomes than patients classified as the other clusters.  相似文献   
68.
Balamuthia mandrillaris is an amoeba found in fresh water and soil that causes granulomatous amoebic encephalitis. We report herein an autopsy case of B. mandrillaris amoebic encephalitis, which was definitely diagnosed by PCR. An 81‐year‐old man, who had Sjögren's syndrome, manifested drowsiness 2 months before his death with progressive deterioration. Neuroimaging demonstrated foci of T2‐ and fluid‐attenuated inversion recovery high and T1 low‐intensity with irregular post‐contrast ring enhancement in the cerebral hemisphere, thalamus and midbrain. Pathologically, multiple hemorrhagic and necrotic lesions were found in the cerebrum, thalamus, midbrain, pons, medulla and cerebellum, which were characterized by liquefactive necrosis, marked edema, hemorrhage and necrotizing vasculitis associated with the perivascular accumulation of amoebic trophozoites, a few cysts, and the infiltration of numerous neutrophils and microglia/macrophages. The trophozoites were ovoid or round, 10–60 μm in diameter, and they showed foamy cytoplasm and a round nucleus with small karyosome in the center. The PCR and immunohistochemistry from paraffin‐embedded brain specimens revealed angioinvasive encephalitis due to B. mandrillaris. Human cases of B. mandrillaris brain infection are rare in Japan, with only a few brief reports in the literature.  相似文献   
69.
Multiple system atrophy (MSA) is an oligodendrogliopathy of presumably sporadic origin, characterized by prominent α‐synuclein inclusions with neuronal multisystem degeneration, although a few Mendelian pedigrees have been reported. Here we report two familial cases of MSA of unknown genetic background. One patient was diagnosed as a possible MSA‐C (cerebellar dysfuntion) case, and the other as clinically possible MSA‐P (parkinsonism), which turned out to be definite MSA, based on a detailed autopsy. The neuropathology showed extensive deposition of α‐synuclein in the glia as well as in the neurons located in the cerebral cortices and hippocampal systems, although neither multiplication of the SNCA gene or mutations in COQ2 gene were identified in the family concerned.  相似文献   
70.
Aims/IntroductionGlucagon‐like peptide‐1 receptor agonists (GLP‐1 RA) might be less effective in patients with severe hyperglycemia, because hyperglycemia downregulated the GLP‐1 receptor in an animal study. To examine this hypothesis clinically, we compared the glucose‐lowering effects of GLP‐1 receptor agonist liraglutide with and without prior glycemic control.Materials and MethodsIn an open‐label, parallel trial, participants with poorly controlled type 2 diabetes were recruited and randomized to receive once‐daily insulin therapy, degludec (Insulin–GLP‐1 RA relay group, mean 16.8 ± 11.4 IU/day), for 12 weeks and then liraglutide for 12 weeks or subcutaneous injections of GLP‐1 RA, liraglutide (GLP‐1 RA first group, 0.9 mg), for 24 weeks. The primary efficacy end‐points consisted of changes in the levels of fasting plasma glucose and glycated hemoglobin (HbA1c).ResultsThe median fasting plasma glucose and HbA1c before the study were 210.0 mg/dL and 9.8%, respectively. The levels of fasting plasma glucose and HbA1c significantly decreased in the Insulin–GLP‐1 RA relay group (P < 0.001) and GLP‐1 RA first group (P < 0.001) by week 24, although no intergroup differences were observed. The reduction of HbA1c in the Insulin–GLP‐1 RA relay group tended to be larger than that in the GLP‐1 RA first group in the lowest CPR (C‐peptide immunoreactivity) quartile (P = 0.072). The adverse events consisted of gastrointestinal problems, followed by hypoglycemia.ConclusionsThe GLP‐1 receptor agonist is overall effective without prior glycemic control with insulin in participants with poorly controlled type 2 diabetes. However, in participants with insulinopenic type 2 diabetes, prior glycemic control with insulin might overcome glucose toxicity‐induced GLP‐1 resistance.  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