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   2133篇
  免费   107篇
  国内免费   37篇
耳鼻咽喉   5篇
儿科学   23篇
妇产科学   13篇
基础医学   198篇
口腔科学   27篇
临床医学   123篇
内科学   676篇
皮肤病学   50篇
神经病学   81篇
特种医学   71篇
外科学   494篇
综合类   12篇
预防医学   59篇
眼科学   62篇
药学   102篇
中国医学   1篇
肿瘤学   280篇
  2023年   23篇
  2022年   54篇
  2021年   83篇
  2020年   48篇
  2019年   77篇
  2018年   67篇
  2017年   56篇
  2016年   75篇
  2015年   71篇
  2014年   89篇
  2013年   84篇
  2012年   126篇
  2011年   157篇
  2010年   72篇
  2009年   85篇
  2008年   117篇
  2007年   120篇
  2006年   127篇
  2005年   113篇
  2004年   91篇
  2003年   86篇
  2002年   82篇
  2001年   20篇
  2000年   23篇
  1999年   29篇
  1998年   26篇
  1997年   11篇
  1996年   17篇
  1995年   14篇
  1993年   11篇
  1992年   15篇
  1991年   8篇
  1990年   19篇
  1989年   19篇
  1988年   21篇
  1987年   27篇
  1986年   13篇
  1985年   14篇
  1984年   11篇
  1983年   9篇
  1979年   8篇
  1977年   8篇
  1976年   8篇
  1975年   3篇
  1973年   3篇
  1972年   4篇
  1971年   6篇
  1969年   6篇
  1968年   3篇
  1966年   4篇
排序方式: 共有2277条查询结果,搜索用时 15 毫秒
31.
A 63-year-old man was admitted to our hospital in March 2017 with dysphagia and right homonymous hemianopsia. We diagnosed him with esophagogastric junction cancer (adenocarcinoma) with metastases to the cerebral occipital lobe, bone, and lymph nodes. After one cycle of 5FU + cisplatin (FP), the brain metastasis was resected because of the hemiplegic symptoms he developed. Histology of the resected tissue showed no viable tumor cells. After three cycles of FP, the primary lesion and metastases were resolved. Upper gastrointestinal endoscopy revealed a scar at the primary site. This was considered a complete response (CR). In April 2018, CT revealed a mass at the cardia, which was considered as lymph node metastases with gastric wall invasion. Although two additional cycles of FP were administered for recurrent tumors, the efficacy was progressive. In August 2018, proximal gastrectomy and D1 + lymph node dissection were performed. The pathological diagnosis was gastric intramural metastases and lymph node metastases (ypN1 [2/22]). Weekly paclitaxel therapy was administered for three months after surgery. Two years have passed since the last surgery without recurrence. We report a rare case of esophagogastric junction cancer with brain, bone, and gastric intramural metastases that responded to combined modality therapy.  相似文献   
32.
Odontology - There is no conclusive evidence regarding a causal relationship between periodontitis and atherosclerosis. In this study, we examined the microbiome in the oral cavity and atheromatous...  相似文献   
33.
The accumulation of uremic toxins is involved in the progression of CKD. Various uremic toxins are derived from gut microbiota, and an imbalance of gut microbiota or dysbiosis is related to renal failure. However, the pathophysiologic mechanisms underlying the relationship between the gut microbiota and renal failure are still obscure. Using an adenine-induced renal failure mouse model, we evaluated the effects of the ClC-2 chloride channel activator lubiprostone (commonly used for the treatment of constipation) on CKD. Oral administration of lubiprostone (500 µg/kg per day) changed the fecal and intestinal properties in mice with renal failure. Additionally, lubiprostone treatment reduced the elevated BUN and protected against tubulointerstitial damage, renal fibrosis, and inflammation. Gut microbiome analysis of 16S rRNA genes in the renal failure mice showed that lubiprostone treatment altered their microbial composition, especially the recovery of the levels of the Lactobacillaceae family and Prevotella genus, which were significantly reduced in the renal failure mice. Furthermore, capillary electrophoresis–mass spectrometry-based metabolome analysis showed that lubiprostone treatment decreased the plasma level of uremic toxins, such as indoxyl sulfate and hippurate, which are derived from gut microbiota, and a more recently discovered uremic toxin, trans-aconitate. These results suggest that lubiprostone ameliorates the progression of CKD and the accumulation of uremic toxins by improving the gut microbiota and intestinal environment.  相似文献   
34.
35.
18O‐labeled water (Water‐18O) is a widely used starting material of 18F‐labeled diagnostic agents in positron emission tomography (PET). Conventionally, Water‐18O has been separated from other stable oxygen isotope species (16O, 17O) by water distillation or nitric oxide distillation. However, conventional methods are costly and may have safety issues. In 2004, we developed the first unit of our novel oxygen isotope separation process by cryogenic oxygen distillation to overcome these issues. To meet the needs of the market, we built a second unit in 2013 and a third in 2016. We are now operating three commercially viable separation units with a total capacity of 600 kg of Water‐18O per year.  相似文献   
36.
37.
38.
39.
40.
Neuroendocrine carcinoma (NEC) of the stomach is an uncommon disease. Because of its rarity, the clinicopathological features are unclear, and there is no consensus on the optimal treatment strategy. This study included five consecutive patients with gastric NEC who underwent surgery from July 2001 to August 2011. Clinical presentation, tumor location, tumor morphology and size, pathology and immunohistochemistry results, and treatment outcome were analyzed retrospectively and discussed. The study cohort of four men and one woman ranged in age from 52 to 84 years, with a median age of 72 years. Positive rates of neuroendocrine markers were 40 % for chromogranin A, 60 % for synaptophysin, 60 % for CD56, 40 % for neuron-specific enolase, and 100 % for p53 protein. Median number of lymph node metastases per patient was 10, with severe lymphatic and venous infiltration, and high Ki-67 labeling index (60–90 %) reported for all patients. Median tumor size was 6 cm. Stage IV disease was diagnosed in three patients; the other two patients showed stage IIIA tumors. After a mean follow-up of 29.8 months, two of the five patients had died of the disease. Although rare, gastric NECs deserve particular attention because of their strong malignant potential associated with an extremely poor prognosis. Such carcinomas demand an aggressive surgical approach followed by chemotherapy and multimodality adjuvant therapy.  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