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   2230篇
  免费   126篇
  国内免费   22篇
耳鼻咽喉   33篇
儿科学   22篇
妇产科学   24篇
基础医学   291篇
口腔科学   38篇
临床医学   146篇
内科学   571篇
皮肤病学   72篇
神经病学   138篇
特种医学   43篇
外科学   442篇
综合类   15篇
一般理论   1篇
预防医学   61篇
眼科学   80篇
药学   206篇
中国医学   15篇
肿瘤学   180篇
  2023年   20篇
  2022年   40篇
  2021年   46篇
  2020年   26篇
  2019年   42篇
  2018年   46篇
  2017年   44篇
  2016年   53篇
  2015年   65篇
  2014年   101篇
  2013年   99篇
  2012年   132篇
  2011年   151篇
  2010年   86篇
  2009年   71篇
  2008年   112篇
  2007年   118篇
  2006年   110篇
  2005年   124篇
  2004年   93篇
  2003年   100篇
  2002年   91篇
  2001年   59篇
  2000年   44篇
  1999年   45篇
  1998年   27篇
  1997年   19篇
  1996年   7篇
  1995年   11篇
  1994年   11篇
  1993年   15篇
  1992年   37篇
  1991年   36篇
  1990年   31篇
  1989年   33篇
  1988年   14篇
  1987年   27篇
  1986年   21篇
  1985年   27篇
  1984年   13篇
  1983年   15篇
  1981年   9篇
  1980年   9篇
  1979年   13篇
  1978年   9篇
  1976年   8篇
  1975年   7篇
  1974年   8篇
  1973年   7篇
  1972年   9篇
排序方式: 共有2378条查询结果,搜索用时 46 毫秒
31.
32.
Atypical progeroid syndrome (APS), including atypical Werner syndrome (AWS), is a progeroid syndrome involving heterozygous mutations in the LMNA gene encoding the nuclear protein lamin A/C. We report the first Japanese case of APS/AWS with a LMNA mutation (p.D300N). A 53‐year‐old Japanese man had a history of recurrent severe cardiovascular diseases as well as brain infarction and hemorrhages. Although our APS/AWS patient had overlapping features with Werner syndrome (WS), such as high‐pitched voice, scleroderma, lipoatrophy and atherosclerosis, several cardinal features of WS, including short stature, premature graying/alopecia, cataract, bird‐like face, flat feet, hyperkeratosis on the soles and diabetes mellitus, were absent. In immunofluorescence staining and electron microscopic analyses of the patient's cultured fibroblasts, abnormal nuclear morphology, an increase in small aggregation of heterochromatin and a decrease in interchromatin granules in nuclei of fibroblasts were observed, suggesting that abnormal nuclear morphology and chromatin disorganization may be associated with the pathogenesis of APS/AWS.  相似文献   
33.
34.
Melatonin plays an important role in regulating circadian rhythms. It also acts as a potent antioxidant and regulates glucose and lipid metabolism, although the exact action mechanism is not clear. The α2‐HS‐glycoprotein gene (AHSG) and its protein, fetuin‐A (FETUA), are one of the hepatokines and are known to be associated with insulin resistance and type 2 diabetes. The aim of this study was to determine whether melatonin improves hepatic insulin resistance and hepatic steatosis in a FETUA‐dependent manner. In HepG2 cells treated with 300 μmol/L of palmitic acid, phosphorylated AKT expression decreased, and FETUA expression increased, but this effect was inhibited by treatment with 10 μmol/L of melatonin. However, melatonin did not improve insulin resistance in FETUA‐overexpressing cells, indicating that improvement in insulin resistance by melatonin was dependent on downregulation of FETUA. Moreover, melatonin decreased palmitic acid‐induced ER stress markers, CHOP, Bip, ATF‐6, XBP‐1, ATF‐4, and PERK. In addition, in the high‐fat diet (HFD) mice, oral treatment with 100 mg/kg/day melatonin for 10 weeks reduced body weight gain to one‐third of that of the HFD group and hepatic steatosis. Insulin sensitivity and glucose intolerance improved with the upregulation of muscle p‐AKT protein expression. FETUA expression and ER stress markers in the liver and serum of HFD mice were decreased by melatonin treatment. In conclusion, melatonin can improve hepatic insulin resistance and hepatic steatosis through reduction in ER stress and the resultant AHSG expression.  相似文献   
35.
Histiocytoses, including Langerhans cell histiocytosis (LCH), juvenile or adult xanthogranuloma (AXG) and Rosai–Dorfman disease (RDD), are rare disorders characterized by the proliferation of cells derived from monocyte/macrophage lineages. A few cases of LCH coexisting with xanthogranuloma or RDD have been reported. The etiology of these diseases remains unclear. However, oncogenic BRAFV600E mutations have been identified in LCH. Here, we report the case of a 26‐year‐old Japanese man with a 3‐month history of a solitary occipital nodule. No abnormality was detected in his other organs, and a total resection of the nodule was performed. Histopathological examination revealed the coexistence of LCH and AXG with prominent emperipolesis characteristic of RDD. Immunohistochemistry showed that most of the large histiocytes were positive for CD68, weakly positive or negative for S100, and negative for CD207 and CD1a, supporting the diagnosis of AXG. The tumor cells with emperipolesis did not show S100‐positive findings characteristic of RDD. The focally aggregated oval histiocytic cells were positive for CD1a, CD207, CD68 and S100, and were compatible with the immunophenotype of LCH cells. In addition, these cells were positive for BRAFV600E mutation. The tumor cells in our patient exhibited a cellular morphology characteristic of multiple histiocytoses in a solitary cutaneous nodule, which may imply an etiological association among LCH, AXG and RDD. To our knowledge, this is the first report of a BRAFV600E mutation‐positive case of LCH coexisting with AXG. Because patients with BRAFV600E mutation have higher risks of multisystemic LCH and recurrence, we should carefully follow up the patient.  相似文献   
36.
37.
As the population ages, the quantity and complexity of comorbidities only increases in the primary care setting. Health systems strive to improve quality of care and enhance cost savings, but current administrative and payment systems do not easily support the implementation of existing evidence and best practices for multimorbid adults in most primary care offices. This perspectives piece sets forth a research agenda in the area of implementation science at the intersection of geriatrics and general internal medicine. We challenge academic medical centers, medical societies, journals, and funders to actively value and support investigation in this area as much as traditional research pathways.  相似文献   
38.
39.
40.
BACKGROUND/AIMS: The anti-cancerous effect on hepatocellular carcinoma of a newly established form of thermotherapy, which uses an implant heating system, was evaluated. As a new material for application in hyperthermia, the authors developed a powder type Mg-ferrite complex that produces heat under a relatively low-power magnetic field. METHODOLOGY: This material suspended in Lipiodol was injected into tumors on the backs of mice that consisted of human hepatocellular carcinoma cells. Hyperthermia was performed by directing a magnetic charge on tumor-bearing mice that contained the Mg-ferrite complex. The temperature of the tumor was kept at 42-43 degrees C, while the magnetic field power ranged from 50 to 80G. RESULTS: A 10-min hyperthermia treatment was insufficiently effective against tumor growth. Systemic injection of doxorubicin (ADM) before hyperthermia appeared to enhance the anti-cancerous effect, but the difference was little and did not reach a statistically significant level (repeated measure analysis of variance). The anticancerous effect of hyperthermia for 15 minutes, in contrast, was marked. The nodules had almost completely disappeared by the end of the experiment. CONCLUSIONS: In conclusion, it is suggested that hyperthermotherapy using this newly developed Mg-ferrite complex might become an option for low-invasive therapy for advanced hepatocellular carcinoma in humans.  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