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   1638篇
  免费   97篇
  国内免费   32篇
耳鼻咽喉   9篇
儿科学   25篇
妇产科学   8篇
基础医学   202篇
口腔科学   41篇
临床医学   117篇
内科学   550篇
皮肤病学   30篇
神经病学   114篇
特种医学   90篇
外科学   220篇
综合类   4篇
预防医学   49篇
眼科学   33篇
药学   84篇
中国医学   5篇
肿瘤学   186篇
  2023年   22篇
  2022年   69篇
  2021年   100篇
  2020年   59篇
  2019年   67篇
  2018年   55篇
  2017年   42篇
  2016年   61篇
  2015年   82篇
  2014年   74篇
  2013年   66篇
  2012年   120篇
  2011年   131篇
  2010年   68篇
  2009年   42篇
  2008年   74篇
  2007年   90篇
  2006年   82篇
  2005年   74篇
  2004年   73篇
  2003年   67篇
  2002年   63篇
  2001年   19篇
  2000年   17篇
  1999年   15篇
  1998年   14篇
  1997年   6篇
  1996年   14篇
  1995年   13篇
  1994年   14篇
  1993年   7篇
  1992年   8篇
  1991年   6篇
  1990年   5篇
  1988年   6篇
  1987年   2篇
  1986年   2篇
  1985年   6篇
  1984年   6篇
  1982年   5篇
  1981年   2篇
  1980年   3篇
  1979年   2篇
  1978年   3篇
  1977年   1篇
  1976年   1篇
  1975年   2篇
  1971年   2篇
  1968年   1篇
  1964年   1篇
排序方式: 共有1767条查询结果,搜索用时 15 毫秒
31.
32.
Background Medication for the relief of heartburn should have the rapid onset of action required for on-demand use. We studied the inhibition of gastric acid secretion by lafutidine and rabeprazole, given in single doses to fasting and postprandial subjects.Methods A total of 22 healthy male, Helicobacter pylori-negative volunteers participated in this randomized, two-way crossover study. They were randomly assigned to receive a single oral dose of 10mg lafutidine or 20mg rabeprazole after fasting overnight (12 subjects, fasting study) or after eating a test meal (noodles, 364kcal; protein, 10.1g; fat, 16g; carbohydrates, 44.9g; NaCl, 1.1g; 10 subjects, postprandial study). Intragastric pH was monitored continuously for 6h after treatment. The other drug was given after a washout period of at least 7 days, and intragastric pH was similarly monitored.Results In the fasting study, lafutidine sustained pH at >3 and >4 during the second, third, fourth, fifth, and sixth hours of the study for significantly longer than rabeprazole. During the first 6h after treatment, lafutidine sustained pH at more than 2, 3, 3.5, 4, 5, 6, and 7 longer than rabeprazole. In the postprandial study, lafutidine sustained pH >3 and >4 for longer periods than rabeprazole during the third, fourth, fifth, and sixth hours of the study. During the first 6h after treatment, lafutidine sustained pH at more than 2, 3, 3.5, 4, 5, 6, and 7 longer than rabeprazole.Conclusions Lafutidine 10mg produces a prompter rise in intragastric pH than rabeprazole 20mg in fasting and postprandial Helicobacter pylori-negative male subjects.  相似文献   
33.
34.
35.
36.
37.
Abstract

Lysophosphatidic acid (LPA) is a bioactive lipid that interacts with G protein-coupled LPA receptors (LPA receptor-1 (LPA1) to LPA6). Here, we investigated the effects of LPA signaling via LPA5 on cellular functions of sarcoma cells by generating Lpar5 overexpressing and Lpar5 knockdown cells from rat osteosarcoma and malignant fibrous histiocytoma cells, respectively. The cell motility activity of Lpar5 overexpressing cells was significantly lower, while Lpar5 knockdown cells showed high cell motility, compared with respective controls. Gelatin zymography showed that LPA5 suppressed the activation of matrix metalloproteinase-2. LPA5 also inhibited the cell motility activity of endothelial cells, correlating with the expression levels of vascular endothelial growth factor genes. These results suggest that LPA signaling via LPA5 negatively regulates the cellular functions of rat sarcoma cells.  相似文献   
38.
39.
Assessment of liver fibrosis in patients with chronic hepatitis C (CHC) is critical for predicting disease progression and determining future antiviral therapy. LecT-Hepa, a new glyco-marker derived from fibrosis-related glyco-alteration of serum alpha 1-acid glycoprotein, was used to differentiate cirrhosis from chronic hepatitis in a single-center study. Herein, we aimed to validate this new glyco-marker for estimating liver fibrosis in a multicenter study. Overall, 183 CHC patients were recruited from 5 liver centers. The parameters Aspergillus oryzae lectin (AOL) / Dature stramonium lectin (DSA) and Maackia amurensis lectin (MAL)/DSA were measured using a bedside clinical chemistry analyzer in order to calculate LecT-Hepa levels. The data were compared with those of seven other noninvasive biochemical markers and tests (hyaluronic acid, tissue inhibitor of metalloproteases-1, platelet count, aspartate aminotransferase-to-platelet ratio index [APRI], Forns index, Fib-4 index, and Zeng's score) for assessing liver fibrosis using the receiver-operating characteristic curve. LecT-Hepa correlated well with the fibrosis stage as determined by liver biopsy. The area under the curve (AUC), sensitivity, and specificity of LecT-Hepa were 0.802, 59.6%, and 89.9%, respectively, for significant fibrosis; 0.882, 83.3%, and 80.0%, respectively, for severe fibrosis; and 0.929, 84.6%, and 88.5%, respectively, for cirrhosis. AUC scores of LecT-Hepa at each fibrosis stage were greater than those of the seven aforementioned noninvasive tests and markers. Conclusion: The efficacy of LecT-Hepa, a glyco-marker developed using glycoproteomics, for estimating liver fibrosis was demonstrated in a multicenter study. LecT-Hepa given by a combination of the two glyco-parameters is a reliable method for determining the fibrosis stage and is a potential substitute for liver biopsy. (HEPATOLOGY 2012).  相似文献   
40.
A girl aged 2 years and 8 months came to our clinic for consultation with regard to unerupted primary mandibular bilateral central incisors. An intraoral examination revealed that the teeth had not emerged into the oral cavity and showed a tooth crown morphology similar to that of the primary mandibular incisors, which appeared in the lingual submucosal area outside of the mandibular dental arch. Periapical radiographs demonstrated that the tooth crowns of both affected teeth were severely displaced to the lingual side. Computed tomography examinations were performed to clarify the three-dimensional positions of the affected teeth and their permanent successors, which revealed that the affected teeth were located in their estimated positions and had a standard root morphology. In addition, the permanent successors, which had not initiated root formation, were located close to the affected teeth. We decided to postpone extraction of the affected teeth and perform periodical examinations until the roots of the permanent successors are sufficiently formed. At the age of 2 years and 10 months, the edge of the tooth crown of the primary mandibular left central incisor was found emerged into the oral cavity. According to her parents, the patient did not complain of the emerging edge and no abnormal conditions were observed around the tooth.  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