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   8308篇
  免费   645篇
  国内免费   72篇
耳鼻咽喉   68篇
儿科学   200篇
妇产科学   73篇
基础医学   980篇
口腔科学   188篇
临床医学   565篇
内科学   2418篇
皮肤病学   381篇
神经病学   439篇
特种医学   399篇
外科学   1423篇
综合类   22篇
一般理论   1篇
预防医学   182篇
眼科学   123篇
药学   465篇
中国医学   9篇
肿瘤学   1089篇
  2024年   6篇
  2023年   119篇
  2022年   104篇
  2021年   458篇
  2020年   221篇
  2019年   296篇
  2018年   368篇
  2017年   335篇
  2016年   354篇
  2015年   337篇
  2014年   433篇
  2013年   446篇
  2012年   752篇
  2011年   765篇
  2010年   387篇
  2009年   315篇
  2008年   520篇
  2007年   581篇
  2006年   512篇
  2005年   473篇
  2004年   381篇
  2003年   299篇
  2002年   247篇
  2001年   37篇
  2000年   29篇
  1999年   30篇
  1998年   32篇
  1997年   28篇
  1996年   20篇
  1995年   15篇
  1994年   13篇
  1993年   14篇
  1992年   16篇
  1991年   15篇
  1990年   9篇
  1989年   12篇
  1988年   5篇
  1987年   8篇
  1986年   6篇
  1985年   6篇
  1984年   6篇
  1983年   4篇
  1981年   1篇
  1980年   2篇
  1979年   1篇
  1978年   1篇
  1977年   2篇
  1973年   3篇
  1969年   1篇
排序方式: 共有9025条查询结果,搜索用时 140 毫秒
81.
Introduction:Uterine fibroids, which are common benign tumors, rarely cause acute complications. We herein report a case of hemoperitoneum associated with uterine fibroid that could be diagnosed preoperatively with contrast-enhanced computerized tomography (CT).Patient concerns:A 48-year-old woman with uterine fibroid developed extremely severe lower abdominal pain on the first day of her menstrual period.Diagnosis:Ultrasonography and contrast-enhanced CT revealed a uterine fibroid and extravasation from the dilated vessels of the uterine fibroid.Intervention:Emergent abdominal hysterectomy was performed.Outcomes:The total amount of bleeding was 4,600 mL. Intraoperative blood salvage (1,357 mL), 6 units of red blood cells, 4 units of fresh frozen plasma, and 20 units of platelet concentrates were transfused. The postoperative course was uneventful. Pathological examination confirmed a benign uterine fibroid.Conclusion:CT could be useful to determine a diagnosis for bleeding from ruptured subserosal uterine fibroid.  相似文献   
82.
BackgroundThe purpose of this study was to investigate residual acetabular retroversion after skeletal maturity in patients with Pemberton osteotomy.Patients and methodsWe compared 40 hips in 36 patients treated with a Pemberton osteotomy (Pemberton group) and 30 hips in 26 patients treated only with a Pavlik harness (Rb group) for developmental dysplasia of the hip. The average age at operation in the Pemberton group was 94.5 months and the follow-up duration was 151.8 months. Radiographic parameters included the acetabular index (a angle) and the center-edge angle of Wiberg, preoperatively and at skeletal maturity. We examined the crossover sign (COS) at the latest follow-up as a sign of acetabular retroversion (AR). We compared the parameters between the two groups and examined the risk factors for acetabular retroversion using a multivariate Cox model.ResultA COS (+) was significantly more frequent in the Pemberton group compared to the Rb group [15 hips (37.5 %) vs 3 hips (10 %); p = 0.0077]. In the Pemberton group, the average age at operation in COS (+) hips was significantly older than that in COS (—) hips (126.9 vs 72.8 months; p = 0.0005). The preoperative α angle did not vary between hips with and without COS; however, the postoperative α angle was significantly smaller in COS (+) hips. A multiple logistic regression analysis for prediction of COS (+) showed that the age at operation and the amount change of α angle were significant predictors for COS (+) hips. The cut-off of the age at operation was 7 years and 9 months old.ConclusionsAR was present in 37.5 % of the hips in the Pemberton group after skeletal maturity. Remodeling of acetabular version was observed in younger patients; however, hips in older patients (> 8 years) at the time of operation and greater degrees of correction tended to result in AR.  相似文献   
83.
The issue of proper use of postmortem computed tomography (PMCT) in forensic fields is currently being actively discussed. The PMCT image has specific findings that differ from the antemortem image, and it is essential to understand and interpret postmortem changes in order to utilize PMCT properly. In this article, we present two cases of acute subdural hematoma (ASDH) in which images were obtained both ante- and postmortem. These images showed marked reduction of hematoma and diminishing midline shift between the agonal and postmortem periods, without evacuation of the hematoma. Attention should be paid to this phenomenon because key findings in determining cause of death could disappear if investigating the cause of death takes too long in cases that prove to be ASDH. In other words, this phenomenon potentially becomes a risk for misdiagnosis when we decide the cause of death without knowing the details of the circumstances of death.  相似文献   
84.
Dermatitis herpetiformis (DH) is common in some Caucasian populations but extremely rare in Japanese, probably because of different immunogenetic backgrounds. We report two Japanese DH cases with typical clinical, histological and direct immunofluorescence features. However, no symptom of gluten‐sensitive enteropathy was shown. The diagnosis was confirmed by eliminating other autoimmune blistering diseases by indirect immunofluorescence, enzyme‐linked immunosorbent assays and immunoblotting. However, circulating immunoglobulin (Ig)A anti‐endomysium, reticulin and gliadin antibodies were not detected. IgA antibodies to tissue and epidermal transglutaminases were also negative. One case was associated with lung cancer and the other one with autoimmune pancreatitis. On review of 17 cases of DH reported in Japan over the previous 10 years, including our cases, one case was associated with gluten‐sensitive enteropathy, four with malignant neoplasms, two with autoimmune systemic disorders and one with psoriasis. Although our cases were typical of DH in clinical, histopathological and IgA deposit features, they showed different human leukocyte antigen haplotypes, no gluten‐sensitive enteropathy and no DH‐specific IgA antibodies, including those to epidermal and tissue transglutaminases. These results suggest that studies of unique characteristics in Japanese DH patients should facilitate further understanding of pathogenesis in DH.  相似文献   
85.
86.
87.
88.
89.
All types of progressive chronic kidney disease (CKD) inevitably induce renal fibrosis, the hallmark of which is the activation and accumulation of a large number of matrix-producing fibroblasts or myofibroblasts. The activated fibroblasts or myofibroblasts are derived from diverse origins, such as residential fibroblasts, vascular pericytes, epithelial-to-mesenchymal transition (EMT), and bone marrow (circulating fibrocytes). Recently, endothelial-to-mesenchymal transition (EndMT) or endothelial-to-myofibroblast transition has also been suggested to promote fibrosis and is recognized as a novel mechanism for the generation of myofibroblasts. Similar to EMT, during EndMT, endothelial cells lose their adhesion and apical–basal polarity to form highly invasive, migratory, spindle-shaped, elongated mesenchymal cells. More importantly, biochemical changes accompany these distinct changes in cell polarity and morphology, including the decreased expression of endothelial markers and the acquisition of mesenchymal markers. This review highlights evidence supporting the important role of EndMT in the development of renal fibrosis in CKD and its underlying mechanisms, including novel biological significance of microRNA regulation.  相似文献   
90.
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