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   64007篇
  免费   4906篇
  国内免费   1781篇
耳鼻咽喉   840篇
儿科学   1212篇
妇产科学   2218篇
基础医学   8076篇
口腔科学   1168篇
临床医学   6892篇
内科学   12011篇
皮肤病学   1209篇
神经病学   3963篇
特种医学   2669篇
外国民族医学   6篇
外科学   8537篇
综合类   4209篇
现状与发展   7篇
一般理论   11篇
预防医学   3504篇
眼科学   1408篇
药学   5356篇
  20篇
中国医学   1680篇
肿瘤学   5698篇
  2023年   522篇
  2022年   1324篇
  2021年   2147篇
  2020年   1310篇
  2019年   1621篇
  2018年   2006篇
  2017年   1520篇
  2016年   1575篇
  2015年   2336篇
  2014年   2923篇
  2013年   3402篇
  2012年   4822篇
  2011年   4697篇
  2010年   2997篇
  2009年   2634篇
  2008年   3547篇
  2007年   3570篇
  2006年   3394篇
  2005年   3125篇
  2004年   2832篇
  2003年   2711篇
  2002年   2356篇
  2001年   1852篇
  2000年   1611篇
  1999年   1341篇
  1998年   569篇
  1997年   474篇
  1996年   439篇
  1995年   389篇
  1994年   371篇
  1993年   247篇
  1992年   713篇
  1991年   588篇
  1990年   538篇
  1989年   493篇
  1988年   428篇
  1987年   429篇
  1986年   363篇
  1985年   300篇
  1984年   233篇
  1983年   191篇
  1982年   116篇
  1981年   124篇
  1980年   101篇
  1979年   207篇
  1978年   165篇
  1977年   115篇
  1976年   112篇
  1975年   103篇
  1974年   99篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
INTRODUCTION Neuroglobin (NGB) is a recently discovered member of the vertebrate globin family [1], predominantly expressed in various brain regions of human and vertebrate. The expression of NGB was increased in case of ischemia, which may play a role in…  相似文献   
142.
The model for end-stage liver disease (MELD) has a better predictive accuracy for survival than the Child-Turcotte-Pugh (CTP) system and has been the primary reference for organ allocation in liver transplantation. The CTP system, with a score range of 5-15, has a ceiling effect that may compromise its predictive power. In this study, we proposed a refined CTP scoring method and investigated its predictive ability. An additional point was given to patients with serum albumin < 2.3 g/dL, bilirubin > 8 mg/dL or prothrombin time prolongation > 11 seconds. The modified CTP system, containing class D, was compared to the MELD and original CTP system in 436 patients. There was a significant correlation between the MELD and modified CTP score (rho = 0.59, P< 0.001). Using mortality as the endpoint, the area under receiver operating characteristic curve for modified CTP system was 0.895 compared with 0.872 for MELD (P = 0.450) and 0.809 for original CTP system (P < 0.001) at 3 months; the area was 0.890, 0.837 and 0.756, respectively (P = 0.051 and < 0.001, respectively) at 6 months. The risk ratio per unit increase for the modified CTP score was 2.7 and 3.08 at 3 and 6 months respectively (P < 0.001). In conclusion, the modified CTP system can be proposed as an alternative prognostic model for cirrhotic patients. By extending the score range according to the influence of the laboratory-derived variables, the modified CTP system has a better performance than the original system and is as efficient as the MELD for outcome prediction.  相似文献   
143.
The serum antibodies to severe acute respiratory syndrome (SARS) coronavirus of 18 SARS patients were checked at 1 month and every 3 months after disease onset. All of them except one, who missed blood sampling at 1 month, tested positive for the immunoglobulin G (IgG) antibody at 1 month. Fifteen out of 17 tested positive for the IgM antibody at 1 month. The serum IgM antibody of most patients became undetectable within 6 months after the onset of SARS. The IgG antibody of all 17 patients, whose serum was checked 1 year after disease onset, remained positive.  相似文献   
144.
145.
795例肺癌术后发生心律失常的多因素分析   总被引:1,自引:0,他引:1  
目的探讨肺癌术后发生心律失常的危险因素及其防治。方法回顾分析2002年1月~2004年1月我院肺癌手术795例,其中全肺切除术176例,肺叶切除术509例,楔型切除术110例。术后发生心律失常273例,应用Logistic回归对影响术后发生心律失常可能的危险因素进行分析。结果本组病例心律失常总发生率为34.3%(273/795),多因素Logistic逐步回归分析显示高龄、吸烟史、心律失常史、全肺切除、术中心包损伤、术后肺不张是术后心律失常的主要危险因素(P〈0.05),术后镇痛是保护因素(P=0.017)。结论心脏的储备功能降低、对手术损伤及缺氧的耐受力降低是导致术后心律失常的原因,采取一些预防措施可以减少其发生率。  相似文献   
146.
OBJECTIVE: To investigate the serial CT findings of Paragonimus westermani infected dogs and the microscopic structures of the worm cysts using Micro-CT. MATERIALS AND METHODS: This study was approved by the committee on animal research at our institution. Fifteen dogs infected with P. westermani underwent serial contrast-enhanced CT scans at pre-infection, after 10 days of infection, and monthly thereafter until six months for determining the radiologic-pathologic correlation. Three dogs (one dog each time) were sacrificed at 1, 3 and 6 months, respectively. After fixation of the lungs, both multi-detector CT and Micro-CT were performed for examining the worm cysts. RESULTS: The initial findings were pleural effusion and/or subpleural ground-glass opacities or linear opacities at day 10. At day 30, subpleural and peribronchial nodules appeared with hydropneumothorax and abdominal or chest wall air bubbles. Cavitary change and bronchial dilatation began to be seen on CT scan at day 30 and this was mostly seen together with mediastinal lymphadenopathy at day 60. Thereafter, subpleural ground-glass opacities and nodules with or without cavitary changes were persistently observed until day 180. After cavitary change of the nodules, the migratory features of the subpleural or peribronchial nodules were seen on all the serial CT scans. Micro-CT showed that the cyst wall contained dilated interconnected tubular structures, which had communications with the cavity and the adjacent distal bronchus. CONCLUSION: The CT findings of paragonimiasis depend on the migratory stage of the worms. The worm cyst can have numerous interconnected tubular channels within its own wall and these channels have connections with the cavity and the adjacent distal bronchus.  相似文献   
147.
148.
OBJECTIVE: We sought to assess the efficacy of facial translocation in the management of tumors of the skull base and paranasal sinuses. STUDY DESIGN AND SETTING: From July 1993 to December 1999, 75 patients, aged 3 to 102 years old, underwent facial translocation. Thirty-three (44%) patients also underwent a combined neurosurgical procedure. Nineteen (25%) had previous surgery. These patients were followed up to 6 years. RESULTS: There were 21 benign and 54 malignant tumors. There were no perioperative deaths. The morbidity rate was 31%. Of the 54 patients with malignant tumors, the actuarial 3-year survival rate was 59%, whereas the local control rate was 54%. CONCLUSION: The facial translocation technique offers favorable exposure of the critical zones of the anterior and middle cranial base, thus facilitating extensive resection and reconstruction. SIGNIFICANCE: This study demonstrates that facial translocation is one of the best surgical approaches to the skull base.  相似文献   
149.
Ching-Hao Chang  MD    Yuan-Li Liao  MD    Hong-Shang Hong  MD  Ph  D 《Dermatologic surgery》2003,29(7):775-779
BACKGROUND: Cutaneous metastasis from adenoid cystic carcinoma of the salivary gland is very rare. OBJECTIVE: To present an unusual case of cutaneous metastasis from adenoid cystic carcinoma of the right parotid gland. METHODS: A 63-year-old woman with multiple subcutaneous nodules on the abdomen and a gradually enlarged mass over the right parotid area was examined. A skin biopsy was taken from one of the abdominal nodules. RESULT: Skin biopsy demonstrated the characteristic histopathologic features of metastatic adenoid cystic carcinoma. A subsequent computerized tomography of the head and neck revealed a huge soft tissue mass involving the right parotid gland. Computerized tomography of the chest revealed extensive nodular pleural thickening, and pleural biopsy also showed typical histopathologic features of metastatic adenoid cystic carcinoma. All of these results are consistent with the diagnosis of an adenoid cystic carcinoma of the right parotid gland with disseminated metastases. CONCLUSION: We report a rare case of cutaneous metastasis from adenoid cystic carcinoma of the right parotid gland. The presentation of cutaneous metastasis is often nonspecific and may mimic benign lesions. Subcutaneous nodules that are rapidly developing or eruptive, are rapidly growing and have stony hardness in nature, have pain or tenderness, and have nonhealing ulceration remind us of the possibility of cutaneous metastases. Dermatologists and dermatologic surgeons should keep the diagnosis of cutaneous metastasis in mind and always perform skin biopsy when encountering these lesions.  相似文献   
150.
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