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   7121篇
  免费   502篇
  国内免费   156篇
耳鼻咽喉   166篇
儿科学   51篇
妇产科学   132篇
基础医学   1142篇
口腔科学   89篇
临床医学   501篇
内科学   1597篇
皮肤病学   273篇
神经病学   652篇
特种医学   403篇
外科学   990篇
综合类   16篇
一般理论   2篇
预防医学   150篇
眼科学   131篇
药学   535篇
中国医学   110篇
肿瘤学   839篇
  2024年   3篇
  2023年   74篇
  2022年   193篇
  2021年   291篇
  2020年   152篇
  2019年   211篇
  2018年   239篇
  2017年   219篇
  2016年   343篇
  2015年   487篇
  2014年   560篇
  2013年   543篇
  2012年   788篇
  2011年   812篇
  2010年   517篇
  2009年   383篇
  2008年   445篇
  2007年   402篇
  2006年   314篇
  2005年   270篇
  2004年   175篇
  2003年   120篇
  2002年   136篇
  2001年   15篇
  2000年   21篇
  1999年   14篇
  1998年   14篇
  1997年   11篇
  1996年   7篇
  1995年   8篇
  1994年   5篇
  1992年   1篇
  1991年   2篇
  1988年   1篇
  1985年   2篇
  1984年   1篇
排序方式: 共有7779条查询结果,搜索用时 15 毫秒
101.
Intestinal obstruction involves a partial or complete blockage of the bowel which results in the failure of intestinal contents to pass through. The mechanical causes of obstruction may include the followings: hernias, postoperative adhesions or scar tissue, impacted feces, gallstones, tumors, granulomatous processes, intussusception, volvulus, foreign bodies, and etc. Hernias are the third leading cause of intestinal obstruction by 10% approximately. However, most hernias are the cases with abdominal wall, inguinal or internal hernia. Femoral, obturator, lumbar, or sciatic hernia as the cause of obsturction is rare. Furthermore, the cases accompanying soft tissue necrosis are seldomly reported. Herein, we report a case of intestinal obstruction caused by strangulated femoral hernia accompanying soft tissue necrosis in a 78-years-old female patient.  相似文献   
102.
103.
The clear cell/lipid‐rich change has been described in neuroendocine tumors in several organs, but rarely observed in the appendix. In this study, we describe the morphologic, immunohistochemical features of incidentally discovered appendiceal carcinoids entirely represented by clear cells in a 22‐year‐old man and a 52‐year‐old woman. Ultrastructual examination demonstrated abundant lipid droplets and dense core granules. The mechanism leading to lipid accumulation in the cytoplasm has not been discovered, but degenerative processes following recurrent inflammatory change might be considered. This uncommon variant of appendiceal classic carcinoid tumors may bear a superficial resemblance to goblet carcinoid and/or appendiceal metastases from clear cell carcinoma. Awareness of clear cell carcinoid of the appendix will prevent incorrect diagnosis and unnecessary aggressive management.  相似文献   
104.

Objectives:

This study was performed to investigate the relationship between the incidence of national notifiable infectious diseases (NNIDs) and meteorological factors, air pollution levels, and hospital resources in Korea.

Methods:

We collected and stored 660 000 pieces of publicly available data associated with infectious diseases from public data portals and the Diseases Web Statistics System of Korea. We analyzed correlations between the monthly incidence of these diseases and monthly average temperatures and monthly average relative humidity, as well as vaccination rates, number of hospitals, and number of hospital beds by district in Seoul.

Results:

Of the 34 NNIDs, malaria showed the most significant correlation with temperature (r=0.949, p<0.01) and concentration of nitrogen dioxide (r=-0.884, p<0.01). We also found a strong correlation between the incidence of NNIDs and the number of hospital beds in 25 districts in Seoul (r=0.606, p<0.01). In particular, Geumcheon-gu was found to have the lowest incidence rate of NNIDs and the highest number of hospital beds per patient.

Conclusions:

In this study, we conducted a correlational analysis of public data from Korean government portals that can be used as parameters to forecast the spread of outbreaks.  相似文献   
105.

BACKGROUND/OBJECTIVES

We investigated the effects of a combination of grape pomace (Vitis labrusca, Campbell Early) and Omija fruit (Schizandra chinensis, Baillon) ethanol extracts on lipid metabolism and antioxidant defense system in diet-induced obese mice.

MATERIALS/METHODS

Forty male C57BL/6J mice were divided into four groups and fed high-fat diet (control group, CON) or high-fat diet added 0.5% grape pomace extract (GPE), 0.05% Omija fruit extract (OFE) or 0.5% GPE plus 0.05% OFE (GPE+OFE) for 12 weeks.

RESULTS

In contrast to the GPE- or OFE-supplemented groups, the GPE+OFE group showed significantly lower body weight and white adipose tissue weights than the CON group. Moreover, GPE+OFE supplementation significantly decreased plasma total cholesterol and increased the plasma HDL-cholesterol/total-cholesterol ratio (HTR) compared to the control diet. The hepatic triglyceride level was significantly lower in the GPE+OFE and GPE groups by increasing β-oxidation and decreasing lipogenic enzyme compared to the CON group. Furthermore, GPE+OFE supplementation significantly increased antioxidant enzyme activities with a simultaneous decrease in liver H2O2 content compared to the control diet.

CONCLUSIONS

Together our results suggest that supplementation with the GPE+OFE mixture may be more effective in improving adiposity, lipid metabolism and oxidative stress in high-fat diet-fed mice than those with GPE and OFE alone.  相似文献   
106.
107.
108.
Journal of Thrombosis and Thrombolysis - Patients with COVID-19 are known to be at risk of developing both venous, arterial and microvascular thrombosis, due to an excessive immuno-thrombogenic...  相似文献   
109.
110.
Autoimmune cholangitis is characterized biochemically by chronic cholestasis and histopathologically by chronic non-suppurative destructive cholangitis. It is associated with positive antinuclear antibody test and negative antimitochondrial antibody test results. Recently, we experienced a case of a 35-year-old woman with autoimmune cholangitis associated with thymoma who presented with pruritis, jaundice, chronic fatigue and anterior chest discomfort. Her laboratory examinations revealed marked increases in levels of serum alkaline phosphatase and gamma-glutamyl transpeptidase. In serological tests, antinuclear antibody was found, but antimitochondrial antibody was not. Liver biopsy findings were compatible with chronic non-suppurative destructive cholangitis. On computed tomography (CT) of the chest, a large anterior mediastinal mass was found. The mass was totally resected and the patient was treated with ursodeoxy cholic acid. Thereafter, her clinical symptoms improved and liver functions completely returned to the normal range. We describe here an uncommon association of autoimmune cholangitis with thymoma, which has not been reported previously in the English-written literature.  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