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   651篇
  免费   28篇
  国内免费   26篇
耳鼻咽喉   1篇
儿科学   31篇
妇产科学   10篇
基础医学   76篇
口腔科学   17篇
临床医学   59篇
内科学   125篇
皮肤病学   27篇
神经病学   41篇
特种医学   23篇
外科学   65篇
综合类   32篇
预防医学   27篇
眼科学   1篇
药学   98篇
中国医学   16篇
肿瘤学   56篇
  2022年   4篇
  2021年   6篇
  2017年   6篇
  2016年   7篇
  2015年   12篇
  2014年   16篇
  2013年   25篇
  2012年   15篇
  2011年   14篇
  2010年   44篇
  2009年   26篇
  2008年   19篇
  2007年   25篇
  2006年   29篇
  2005年   19篇
  2004年   13篇
  2003年   13篇
  2002年   13篇
  2001年   15篇
  2000年   15篇
  1999年   23篇
  1998年   26篇
  1997年   28篇
  1996年   21篇
  1995年   22篇
  1994年   13篇
  1993年   19篇
  1992年   13篇
  1991年   11篇
  1990年   15篇
  1989年   16篇
  1988年   15篇
  1987年   14篇
  1986年   19篇
  1985年   12篇
  1984年   13篇
  1983年   7篇
  1982年   4篇
  1980年   3篇
  1979年   6篇
  1978年   7篇
  1977年   3篇
  1965年   4篇
  1964年   7篇
  1963年   4篇
  1962年   3篇
  1959年   4篇
  1958年   7篇
  1955年   4篇
  1911年   2篇
排序方式: 共有705条查询结果,搜索用时 15 毫秒
61.
We investigated the trace element status in Crohn's disease (CD) patients receiving enteral nutrition, and evaluated the effects of trace element-rich supplementation. Thirty-one patients with CD were enrolled in this study. All patients were placed on an enteral nutrition regimen with Elental(R) (Ajinomoto pharmaceutical. Ltd., Tokyo, Japan). Serum selenium, zinc and copper concentrations were determined by atomic absorption spectroscopy. Serum selenoprotein P levels were determined by an ELISA system. Average serum levels of albumin, selenium, zinc and copper were 4.1 +/- 0.4 g/dl, 11.2 +/- 2.8 microg/dl, 71.0 +/- 14.8 microg/dl, and 112.0 +/- 25.6 microg/dl, respectively. In 9 patients of 31 CD patients, serum albumin levels were lower than the lower limit of the normal range. Serum selenium, zinc and copper levels were lower than lower limits in 12 patients, 9 patients and 1 patient, respectively. Serum selenium levels significantly correlated with both serum selenoprotein P levels and glutathione peroxidase activity. Supplementation of selenium (100 microg/day) and zinc (10 mg/day) for 2 months significantly improved the trace element status in CD patients. In conclusion, serum selenium and zinc levels are lower in many CD patients on long-term enteral nutrition. In these patients, supplementation of selenium and zinc was effective in improving the trace element status.  相似文献   
62.
63.
64.
Anticoagulation in CHADS2 Score 1 . Background: The revised ACC/AHA/ESC 2006 guideline recommends either aspirin or warfarin for the prevention of ischemic stroke in patients with atrial fibrillation (AF) in CHADS2 score 1. We hypothesized that warfarin is superior to aspirin therapy for the prevention of stroke without increasing bleeding complication in AF patients with CHADS2 score 1. Methods and Results: Among 1,502 patients (mean 62.4 ± 13.8 years old, male 65.4%) who were treated for nonvalvular AF without previous stroke, the number of patients with CHADS2 score 1 was 422 (62.9 ± 10.7 years old, male 290 [68.7%]) and their antithrombotic therapies were as follows: warfarin (n = 143), aspirin (n = 124), other antiplatelet (n = 45), and no antithrombosis (none: n = 110). We reviewed the incidences of ischemic stroke, mortality, and bleeding complications during the follow‐up period. Results were: (1) during 22.3 ± 17.8 months of follow‐up, the incidence of ischemic stroke was significantly lower in warfarin (6 patients, 4.2%, mean international normalized ratio [INR] 2.0 ± 0.5 IU) than in aspirin (16 patients, 12.9%, P = 0.008) than none (23 patients, 20.9%, P < 0.001) without differences in all‐cause mortality. (2) The incidence of major bleeding (decrease in hemoglobin ≥2 g/dL, requiring hospitalization or red blood cell transfusion ≥2 pints) was not different between warfarin (2.1%) and aspirin (0.8%, P = NS), but minor bleeding was more common in warfarin (10.5%) than in aspirin (2.4%, P = 0.007). Conclusion: In AF patients with CHADS2 score 1, warfarin was better to prevent ischemic stroke than aspirin without increasing the incidence of major bleeding complications. However, the incidence of minor bleeding was higher in the warfarin group than the aspirin group. (J Cardiovasc Electrophysiol, Vol. 21, pp. 501‐507, May 2010)  相似文献   
65.
目的探讨胫骨高位截骨术对随后进行的全膝关节置换术的影响。方法对23例行胫骨高位截骨术后行全膝关节置换术患者的术中情况以及术后膝关节功能与对照组进行了比较,两组患者在年龄、疾病和关节畸形方面具有可比性。结果胫骨高位截骨术后行全膝关节置换术患者的手术时间(118.5±32)与对照组(98.9±20.5)比较差异有统计学意义,伤口的并发症也较对照组多。但两组患者的围手术期的出血量和术后膝关节功能比较差异无统计学意义。结论胫骨高位截骨术后行全膝关节置换术患者的膝关节功能和活动范围与对照组相似,但其手术的技术要求较高,并发症也相对较多。  相似文献   
66.
Boxing is an official sport at the 2008 Beijing Olympic Games and the fast development of world-class high strength training and sport science has made a significant impact on scientific training. Boxing needs high cardio-respiratory function, speed, muscle strength, and anaerobic and intensive physical demands including weight control covering the grading of athlete's body weight and balancing physical ability and health. Sport training is important even for talented athletes. Weight cycling is a term used to describe rapid weight loss following self food limitation and/or dehydration. Both gradual (seasonal) reduction cycles are used and rapid (weekly) weight by athletes,  相似文献   
67.
Boxing is an official sport at the 2008 Beijing Olympic Games and the fast development of world-class high strength training and sport science has made a significant impact on scientific training. Boxing needs high cardio-respiratory function, speed, muscle strength, and anaerobic and intensive physical demands including weight control covering the grading of athlete's.  相似文献   
68.
PURPOSE: To identify loci concerned with radiosensitivity in a mouse model using single nucleotide polymorphism (SNP) markers. MATERIALS AND METHODS: We subjected 276 second filial generation (F2) mice descended from two inbred mouse strains, radiation-induced apoptosis sensitive C57BL/6JNrs (B6) and radiation-induced apoptosis resistant C3H/HeNrs (C3H), to 2.5 Gy whole-body irradiation. We quantified jejunal crypt apoptosis, performed a genome-wide survey, and identified quantitative trait loci (QTL) associated with radiation sensitivity. We expressed apoptosis levels as an apoptotic score (AS), which was equal to the number of apoptotic bodies divided by the number of crypts. We genotyped the mice for 109 SNP markers. RESULTS: AS values were 97.7+/-32.9 in B6 mice and 49.0+/-24.9 in C3H mice (p < 0.01). Genome-wide analysis revealed 8 markers (2 on chromosome 9, 4 on 15, 1 on 17, and 1 on 18) affecting radiation-induced jejunal apoptosis with log odds (LOD) scores ranging from 2.11+/-3.91. We found a significant locus on chromosome 15, which was previously reported by Weil and colleagues. CONCLUSION: These findings support the view that the radiosensitivity of clinically normal tissue depends on variations in several genes.  相似文献   
69.
Park SW, Chung NG, Hur SY, Kim HS, Yoo NJ, Lee SH. Mutational analysis of hypoxia‐related genes HIF1α and CUL2 in common human cancers. APMIS 2009; 117: 880–5. Hypoxia is a general feature of solid cancer tissues. Hypoxia upregulates hypoxia‐inducible factor 1α (HIF1α) that transactivates downstream genes and contributes to cancer pathogenesis. HIF1α is upregulated not only by hypoxia but also by genetic alterations in HIF1α‐related genes, including VHL. Cullin 2 (CUL2) interacts with the trimeric VHL‐elongin B‐elongin C complex and plays an essential role in the ubiquitinated degradation of HIF1α. The aim of this study was to explore whether HIF1α and CUL2 genes are somatically mutated, and contribute to HIF1α activation in common human cancers. For this, we have analyzed the coding region of oxygen‐dependent degradation domain of HIF1α in 47 colon, 47 gastric, 47 breast, 47 lung, and 47 hepatocellular carcinomas, and 47 acute leukemias by a single‐strand conformation polymorphism assay. In addition, we analyzed mononucleotide repeat sequences (A8) in CUL2 in 55 colorectal and 45 gastric carcinomas with microsatellite instability (MSI). We found one HIF1α mutation (p.Ala593Pro) in the hepatocellular carcinomas (1/47; 2.1%), but none in other cancers. We found two CUL2 frameshift mutations in colon cancers (p.Asn292MetfsX20), which were exclusively detected in high MSI cancers (4.9%; 2/41). Our data indicate that somatic mutation of HIF1α is rare in common cancers, and somatic mutation of CUL2 occurs in a fraction of colorectal cancers (colorectal cancers with high MSI). The data suggest that neither HIF1α nor CUL2 mutation may play a central role in HIF1α activation in gastric, colorectal, breast, lung and hepatocellular carcinomas, and acute leukemias.  相似文献   
70.
Villin1 (VIL1) has a role in regulating actin dynamics, cell morphology, anti-apoptotic mechanisms, and epithelial-to-mesenchymal transition. Previously we reported VIL1 as a novel diagnostic marker for cervical adenocarcinoma (AC) with poor radioresponse. This study further investigated the diagnostic role of VIL1 in gynecological tumors especially endometrial AC. We recruited 107 patients with AC (41 tumors in the corpus and 66 tumors in cervix), most of whom treated by total abdominal hysterectomy. Immunohistochemical analysis revealed VIL1-positive tumors in 37% of cases; 10 of 41 corpus tumors and 30 of 66 tumors in the cervix. VIL1-positive tumors were further examined histologically and immunostained for epithelial cell surface marker, EpCAM, and mesenchymal stem cell marker, CD44. Most of these tumors were CD44 negative and EpCAM positive, and the cytoplasmic VIL1 immunoreactivity in endometrial AC was more selective than EpCAM in reflecting histological aggressiveness with high grade nuclear atypia. This study confirmed our previous finding of VIL1 as a diagnostic marker of cervical AC. In addition, VIL1 immunostaining was detected in 25% of endometrial AC cases. These results suggested the existence of an aggressive and VIL1-positive subtype of gynecological tumor.  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