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   404篇
  免费   24篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   16篇
妇产科学   11篇
基础医学   61篇
口腔科学   16篇
临床医学   46篇
内科学   113篇
皮肤病学   10篇
神经病学   20篇
特种医学   20篇
外科学   58篇
预防医学   9篇
眼科学   10篇
药学   4篇
肿瘤学   33篇
  2024年   2篇
  2023年   6篇
  2022年   3篇
  2021年   12篇
  2020年   8篇
  2019年   9篇
  2018年   8篇
  2017年   15篇
  2016年   18篇
  2015年   13篇
  2014年   14篇
  2013年   22篇
  2012年   32篇
  2011年   25篇
  2010年   18篇
  2009年   24篇
  2008年   29篇
  2007年   33篇
  2006年   20篇
  2005年   22篇
  2004年   20篇
  2003年   16篇
  2002年   19篇
  2001年   15篇
  2000年   14篇
  1999年   6篇
  1998年   5篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1992年   1篇
  1988年   2篇
  1986年   1篇
  1980年   1篇
排序方式: 共有436条查询结果,搜索用时 15 毫秒
41.
OBJECTIVES: Aim of this study was to evaluate implication of pregnancy induced hypertension on maternal plasma lipid, lipoprotein, apolipoprotein concentrations and lipid peroxidation products by a comparison of normal pregnancy vs. preeclampsia. DESIGN AND METHODS: Thirty-four women with preeclampsia and 32 healthy pregnant women (controls) in the third trimester were recruited for this study. RESULTS: In the preeclamptic group plasma total triglyceride, low density lipoprotein cholesterol (LDL-C), malondialdehyde (MDA) and apolipoprotein B (apo-B) were significantly increased, while plasma high density lipoprotein cholesterol (HDL-C) was significantly decreased compared to that of control group. There was no significant difference in total cholesterol and apolipoprotein A1 (apo-A1) concentrations. CONCLUSION: Our findings suggest that preeclampsia share some metabolic characteristics with coronary artery disease such as dislipidemia and increased lipid peroxidation. However lipoprotein concentrations may be better biochemical markers of dislipidemia in the preeclamptic state than the corresponding apolipoproteins.  相似文献   
42.
BACKGROUND: We determined complement and immunoglobulin levels in ascitic fluid and serum of 47 patients with spontaneous bacterial peritonitis, malignant ascites, or tuberculous ascites. METHODS: Paracentesis was done to confirm the underlying cause of ascites. Biochemical, hematologic, and microbiologic investigations were also done. RESULTS: The highest serum and ascitic fluid C3 and C4 levels and ascitic fluid IgM, IgA, and IgG levels were found in patients with tuberculosis. Ascitic fluid C3 level was found to be higher in the tuberculous group than in the patients with spontaneous bacterial peritonitis or malignant ascites. Ascitic fluid C4 levels were higher in patients with tuberculosis than in those with spontaneous bacterial peritonitis. CONCLUSION: We believe that further studies of the in vivo kinetics of immunoglobulins and complement in ascitic fluid of various causes are necessary for a better understanding of the host defense mechanisms of these fluids.  相似文献   
43.
44.
Human congenital anomalies of the kidney and urinary tract (CAKUT) represent the major causes of chronic renal failure (CRF) in children. This set of disorders comprises renal agenesis, hypoplasia, dysplastic or double kidneys, and/or malformations of the ureter. It has recently been shown that mutations in several genes, among them BMP4, are associated with hereditary renal developmental diseases. In BMP4, we formerly identified three missense mutations (S91C, T116S, N150K) in five pediatric CAKUT patients. These BMP4 mutations were subsequently studied in a cellular expression system, and here we present functional data demonstrating a lower level of messenger RNA (mRNA) abundance in Bmp4 mutants that indicates a possible negative feedback of the mutants on their own mRNA expression and/or stability. Furthermore, we describe the formation of alternative protein complexes induced by the S91C-BMP4 mutation, which results in perinuclear endoplasmic reticulum (ER) accumulation and enhanced lysosomal degradation of Bmp4. This work further supports the role of mutations in BMP4 for abnormalities of human kidney development.  相似文献   
45.
Gastrointestinal stromal tumor (GIST) represents the most common mesenchymal malignancy of the gastrointestinal (GI) tract. In neurofibromatosis (NF), the increased incidence of tumor needs to be considered even in non-symptomatic individuals. Patients with neurofibromatosis NF type 1 have an increased risk of developing GI tumors including rare types such as GIST. We report a case of GIST in a 53-year-old male patient with neurofibromatosis. The patient was diagnosed with NF four years ago and his medical history revealed that he was hospitalized 5 times with a provisional diagnosis of massive lower gastrointestinal bleeding. GIST was diagnosed at explorative laparotomy and the tumor was 21 cm × 13 cm × 7 cm in size. Immunohistochemical examination showed that vimentin, actin and CD117 were positive. Computerized tomography showed peritoneal implants three months later. Imatinib mesylate (600 mg/d) was initiated. However, control computerized tomography revealed liver and omental metastasis. The dosage was elevated to 800 mg/d. Despite high dosage, the progression of the metastatic lesions continued in the liver and omentum. The patient started oral sunitinib malate (Sutent? Pfizer Inc, New York, NY, USA) 50 mg per day for 4 consecutive weeks, followed by 2 wk off per treatment cycle. The metastatic lesions in the liver and omentum were decreased in size after four courses, suggesting that sunitinib is also an effective treatment modality for metastatic GIST in NF patients.  相似文献   
46.
Renal hypodysplasia (RHD) is characterized by reduced kidney size and/or maldevelopment of the renal tissue following abnormal organogenesis. Mutations in renal developmental genes have been identified in a subset of affected individuals. Here, we report the first mutations in BMP4 and SIX2 identified in patients with RHD. We detected 3 BMP4 mutations in 5 RHD patients, and 3 SIX2 mutations in 5 different RHD patients. Overexpression assays in zebrafish demonstrated that these mutations affect the function of Bmp4 and Six2 in vivo. Overexpression of zebrafish six2.1 and bmp4 resulted in dorsalization and ventralization, respectively, suggesting opposing roles in mesendoderm formation. When mutant constructs containing the identified human mutations were overexpressed instead, these effects were attenuated. Morpholino knockdown of bmp4 and six2.1 affected glomerulogenesis, suggesting specific roles for these genes in the formation of the pronephros. In summary, these studies implicate conserved roles for Six2 and Bmp4 in the development of the renal system. Defects in these proteins could affect kidney development at multiple stages, leading to the congenital anomalies observed in patients with RHD.  相似文献   
47.
Introduction A higher frequency of second malignancies is observed in patients with prostate cancer. We report a case of indolent non-Hodgkin's lymphoma diagnosed 2 years after prostate carcinoma. Case report A 65-year-old man with diagnosis of localized prostate adenocarcinoma was presented with fatigue 2 years after prostatectomy operation. Abdominal ultrasonography showed hepatomegaly and paraaortocaval, parailiac, and perivascular multiple lymph nodes. The complete blood count revealed anemia and thrombocytopenia. Bone marrow biopsy demonstrated small lymphocytic lymphoma. Conclusion Lymphoma should be suspected in cases with newly appeared adenopathy and/or cytopenias during follow-up. In patients with clinically organ-confined prostate cancer, indolent lymphoma should be in the differential diagnosis of newly appeared lymphadenopathy.  相似文献   
48.
Benign causes of increased serum CA-125 concentration   总被引:1,自引:0,他引:1  
  相似文献   
49.
Breast cancer is the most common malignancy in women. However, metastases to the breast from nonmammary malignant neoplasms are rare and were detected at a rate of 0.28% in our series. Clinical and pathologic findings in 5 cases of metastatic tumors (malign mesenchymal tumor, squamous cell carcinoma of the tongue, non-Hodgkin lymphoma, and Sézary syndrome) in the breast are presented and discussed with respect to the literature. Detailed clinical history and a multidisciplinary approach are useful in establishing correct diagnosis and preventing unnecessary radical surgery.  相似文献   
50.
A 3-year-old female patient presented with symptoms of cyanosis and intermittent eyelid edema, leading to the discovery of a lobulated mass in the right atrium, obstructing the superior vena cava. Despite the inability to entirely remove the mass due to its origins in the right atrium myocardium and its extension towards the sinoatrial node, successful surgical intervention and subsequent histopathological evaluation identified the mass as a fibroma, and postoperative symptoms were significantly alleviated.  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