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   159119篇
  免费   6800篇
  国内免费   520篇
耳鼻咽喉   2692篇
儿科学   4666篇
妇产科学   3681篇
基础医学   21452篇
口腔科学   5801篇
临床医学   10050篇
内科学   38656篇
皮肤病学   5034篇
神经病学   12815篇
特种医学   3581篇
外国民族医学   2篇
外科学   19485篇
综合类   972篇
一般理论   43篇
预防医学   15475篇
眼科学   3466篇
药学   11128篇
中国医学   896篇
肿瘤学   6544篇
  2023年   1024篇
  2022年   1754篇
  2021年   4299篇
  2020年   2144篇
  2019年   4053篇
  2018年   5771篇
  2017年   3416篇
  2016年   3306篇
  2015年   3727篇
  2014年   4997篇
  2013年   7112篇
  2012年   11184篇
  2011年   12055篇
  2010年   6347篇
  2009年   4917篇
  2008年   9284篇
  2007年   9809篇
  2006年   9082篇
  2005年   8979篇
  2004年   8028篇
  2003年   7455篇
  2002年   6914篇
  2001年   4438篇
  2000年   4998篇
  1999年   3907篇
  1998年   860篇
  1997年   658篇
  1996年   542篇
  1995年   475篇
  1994年   386篇
  1993年   313篇
  1992年   1497篇
  1991年   1259篇
  1990年   1137篇
  1989年   931篇
  1988年   808篇
  1987年   746篇
  1986年   754篇
  1985年   644篇
  1984年   464篇
  1983年   388篇
  1979年   434篇
  1975年   302篇
  1974年   384篇
  1973年   392篇
  1972年   329篇
  1971年   358篇
  1970年   327篇
  1969年   345篇
  1968年   304篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
62.
IntroductionTo analyse the effectiveness and safety of the indwelling pleural catheter in the management of recurrent malignant pleural effusion.Patients and methodsA prospective multicentre study was performed in 63 consecutive outpatients from four Spanish hospitals. A total of 43 men and 20 women were included, with a median age of 67 years. In seven of the cases treatment with pleurodesis had failed; in five other cases their lung was trapped; in another five cases after repeat therapeutic thoracocentesis, and the rest of them as a preference choice to pleurodesis. All patients had an indwelling pleural catheter inserted (PleurX®, Denver Biomedical).ResultsMost of patients (94.5%) reported an improvement in their respiratory symptoms (cough and dyspnoea) and their ability to function independently. Average length of the catheterisation was 45 days (6-222). Average amount of drained pleural effusion was 75 ml, with a frequency of drainage of between 3 and 4 times per week and once fortnightly. Spontaneous pleurodesis was achieved following 34.9% of procedures. No complications occurred during the insertion of the catheter. The post-catheterisation complications were empyema (3 cases), chest pain (2 cases), and tumour metastasis (3 cases).ConclusionsThe use of an indwelling pleural catheter is an effective palliative treatment in the outpatient management for patients suffering malignant pleural effusion. It is also a simple treatment that can be easily applied, does not require hospitalisation and can be easily managed by the patient at home, with a low rate of complications.  相似文献   
63.
Abstract  Upper gastrointestinal (GI) symptoms occur frequently in the general population, making them among the most common indications responsible for patients consulting the healthcare system. Consequently, understanding and characterization of the upper GI symptoms is important for the diagnosis and assessment of organ dysfunction. In practice, assessment of clinical symptoms is difficult and it is still to a large extent unclear how sensitivity, volume and tone contribute to visceral perception in the upper GI tract. The goal of advanced research in upper GI symptoms is to obtain a better understanding of the mechanisms involved in transduction, transmission, and perception under normal and pathophysiological conditions. An important step towards this goal is understanding the information provided by and the inherent limitations of the currently available measuring techniques. This article focuses on the sensory testing of the oesophagus, and methods and concepts used to assess the relation between gastric volumes or tone and upper GI symptoms. It also summarizes the contributions of these techniques towards identifying the components responsible for the generation of upper GI symptoms.  相似文献   
64.
AIMS: The aims of our study were to determine if insulin resistance is associated with increased plasma levels of non-esterified fatty acids (NEFA), glycerol, 3-hydroxybutyrate and triglycerides in obese children. We also studied whether the presence of acanthosis nigricans (AN) led to further alterations in the above parameters. METHODS: A total of 101 children were studied on their first visit to the paediatric endocrine clinic. Seventy-four were obese, 30 of them with AN. The remaining 27 were non-obese healthy children (control group). NEFAs, glycerol, triglycerides, 3-hydroxybutyrate, insulin, leptin, adiponectin and glucose were determined in blood samples obtained after overnight fasting. The insulin resistance index (IRI) was calculated following the homeostasis model assessment (HOMA). Data from the three groups were compared using appropriate statistical tests. RESULTS: No differences in age, sex ratio and pubertal stage were observed among the three groups. The group of children with the highest body mass index (BMI) showed higher plasma levels of insulin and leptin, higher IRI and lower plasma levels of adiponectin. As insulin and IRI increased, NEFA and 3-hydroxybutyrate decreased and triglycerides increased. When obese children were categorized by BMI, the presence of AN further exacerbated these differences. CONCLUSIONS: In obese children, insulin resistance is associated with plasma lipid alterations suggestive of both decreased adipose tissue lipolysis and hepatic beta-oxidation and increased hepatic synthesis of triglycerides. Such a metabolic condition may facilitate fat storage and hinder weight loss.  相似文献   
65.
66.
67.
Neurologic complications are common after transplantation and affect 30-60% of transplant recipients. The etiology of most of the posttransplant neurologic disorders is related to the opportunistic infections, both systemic and involving central nervous system (CNS), toxicity of immunosuppressive medications, and the metabolic insult created by the underlying primary disease and the transplant procedure. Neuroimaging studies are one of the key tools in the evaluation and enable early diagnosis of neurologic complications in transplant patients, especially posterior reversible leukoencephalopathy syndrome, central pontine myelinolysis, intracerebral hemorrhage, and fungal and bacterial abscesses. Magnetic resonance imaging (MRI) is the preferred technique, but each of the available neuroimaging techniques offers a unique insight into the pathophysiologic mechanisms underlying neurologic complications of transplantation. The role of neuroimaging in this population includes early detection of calcineurin inhibitor neurotoxicity, opportunistic infections, neoplasia, metabolic disorders, or cerebrovascular diseases. In addition, we can monitor longitudinal progression of disease and treatment response.  相似文献   
68.
Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques.  相似文献   
69.
Five patients with idiopathic transient osteoporosis were examined. Bone scanning and MRI was helpful in the diagnosis to differentiate of necrosis and all patients recovered completely with conservative and symptomatic treatment. There was no history of trauma in all patients. MRI was realized previously in all cases to confirm the diagnosis and after the resolution of symptomathology.  相似文献   
70.
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