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   9871篇
  免费   588篇
  国内免费   256篇
耳鼻咽喉   113篇
儿科学   87篇
妇产科学   218篇
基础医学   669篇
口腔科学   342篇
临床医学   1602篇
内科学   1099篇
皮肤病学   129篇
神经病学   338篇
特种医学   418篇
外国民族医学   1篇
外科学   2793篇
综合类   890篇
预防医学   683篇
眼科学   190篇
药学   632篇
  5篇
中国医学   205篇
肿瘤学   301篇
  2024年   18篇
  2023年   148篇
  2022年   238篇
  2021年   340篇
  2020年   315篇
  2019年   343篇
  2018年   349篇
  2017年   283篇
  2016年   349篇
  2015年   289篇
  2014年   603篇
  2013年   561篇
  2012年   487篇
  2011年   552篇
  2010年   450篇
  2009年   422篇
  2008年   428篇
  2007年   461篇
  2006年   398篇
  2005年   334篇
  2004年   317篇
  2003年   294篇
  2002年   226篇
  2001年   237篇
  2000年   141篇
  1999年   156篇
  1998年   126篇
  1997年   135篇
  1996年   152篇
  1995年   111篇
  1994年   120篇
  1993年   126篇
  1992年   115篇
  1991年   138篇
  1990年   108篇
  1989年   99篇
  1988年   119篇
  1987年   80篇
  1986年   92篇
  1985年   86篇
  1984年   80篇
  1983年   64篇
  1982年   53篇
  1981年   47篇
  1980年   64篇
  1979年   14篇
  1978年   11篇
  1977年   7篇
  1975年   6篇
  1974年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Clinical decisions are often made with incomplete information, yet patient care decisions are made every day. Patients vary clinically, uncertainty exists in diagnostic and prognostic information, and many preventive and treatment alternatives have not been formally assessed for their effectiveness. Because scientific information will never answer all clinical questions, clinical decisions are partially based on probabilistic information.
This paper describes how to apply clinical decision making to diagnosing and managing dental caries and periodontal diseases. By using explicit information to quantify probabilities and outcomes, clinical decision making analyzes decisions made under uncertain conditions and the uncertain impact of clinical information.
Clinical decision making incorporates concepts for preventing, diagnosing and treating dental caries and periodontal diseases: risk assessment, evidence-based dentistry, and multiple oral health outcomes. This information can serve as a tool for clinicians to augment clinical judgment and expertise.  相似文献   
12.
Background The Retinal Thickness Analyser (RTA) is intended to detect glaucomatous changes as well as macular pathologies at the posterior pole. We determined the diagnostic accuracy for eyes with manifest glaucoma or macular diseases.Methods We examined 71 eyes with long-term, established eye conditions. Included were 28 eyes with glaucoma, 21 with different macular diseases and 22 normal eyes. All examinations were evaluated in a blind-test by RTA experts without any clinical information on the patients. After comparison of the RTA interpretation with the clinical diagnosis, we determined sensitivity, specificity, positive and negative predictive values.Results Of 71 examinations, 15 (21%) were not interpretable. If these results are excluded, the following diagnostic accuracy values were calculated for glaucoma and macular disorders respectively: sensitivity 75 and 59%, specificity 55 and 97%, positive predictive value 48 and 90% and negative predictive value 80 and 84%. These values were not significantly different when both eyes of each patient were included in the final analysis (n=133).Conclusion The diagnostic values of the RTA determined in this case control study were not satisfactory. However, no clinical information was used in the assessment. The extent to which additional clinical information increases the diagnostic value remains to be determined.  相似文献   
13.
14.
马来酸罗格列酮胃漂浮型缓释片的研究   总被引:10,自引:0,他引:10       下载免费PDF全文
目的:根据流体动力学平衡控释原理(HBS)研制了马来酸罗列酮胃漂浮型缓释片。方法;以体外释放度和漂浮情况为筛选指标,采用单因素考察和正交试验设计相结合, 对胃漂浮缓释片的处方、制备工艺及体外释放条件进行优化筛选;采用γ闪烁照相技术对优化处方的内漂浮情况进行胃内动态观察。结果:马来酸罗格列酮胃漂浮缓释片在释放介质中迅速起漂,持漂时间超过12h,12h达最大累积释放;初步确定在胃内滞留时间达3h以上。结论:优化处方的释放过程符合Higuchi方程,释放机制为异常扩散;胃漂浮片在胃滞时间明显长于普通片。  相似文献   
15.
目的探索以虚拟现实技术为基础的枢椎椎弓根螺钉置人方法。方法选取8具成人颅一颈椎标本,采用改良四柱式定位框架固定于枕颈,使颅-颈-肩形成统一刚体,保持空间位置恒定,CT薄层扫描获取枢椎三维定位信息,采用Aero—Tech立体定向手术规划系统三维建模,设计安全、可视化、个体化的虚拟置钉路径,反复虚拟演示验证钉道安全后,导向弓把持下置人导向钢针,复查CT评价置钉的准确性。结果16个枢椎椎弓根置钉过程中,方向出现偏差(横突孔突破)1个,失败率为6.25%。结论目标椎弓根的容积三维重建、置钉路径可视化设计和虚拟演示,使操作过程简单、直观而精确,不需要线形和角性参数的测量;加上导向抓持装置提供的稳定性,使该技术具有很好的临床应用前景。  相似文献   
16.
微创锁定加压接骨板内固定治疗胫骨骨折   总被引:2,自引:1,他引:1  
林峰  李国山  郭春仙  林宗锦 《中国骨伤》2007,20(12):853-854
臀肌挛缩症的手术治疗方法较多,我们采用大转子后上方双侧小“S”微创切口,每侧切口长约2~3 cm,对挛缩组织进行切断,广泛松解,重症患者行臀中小肌“Z”形延长,松解髋关节囊,并行屈膝屈髋、交叉架腿、划圈征等各项指标评价,配合术后早期功能锻炼治疗,效果满意,1997-2005年8月,共收治2 518例患者,重点研究讨论其病因、分类及治疗。1临床资料1·1诊断臀肌挛缩症的诊断包括病史,特别是婴儿期臀部反复肌肉注射史,特有的外“八”字步态,并膝下蹲困难,站立时的尖臀征,快步行走或跑步时呈跳步征。臀部触诊时可触及索带硬块,划圈征、二郎腿试验及平…  相似文献   
17.
Coagulation screening before epidural analgesia in pre-eclampsia   总被引:1,自引:0,他引:1  
A questionnaire survey of current practice at a small cross-section of obstetric units, covering 22% of all United Kingdom deliveries, revealed a marked lack of standard practice regarding requests for coagulation screens on pre-eclamptic patients who require epidural procedures. A retrospective audit was therefore carried out on 434 coagulation screens requested for pre-eclamptic patients in whom epidural analgesia might have been considered. Borderline abnormalities of coagulation were found in only 10 patients (2%). Platelet counts of less than 150 x 10(9)/litre were present in 28% of cases. 'Significant' thrombocytopenia (less than 100 x 10(9)/litre) and all coagulation abnormalities were only encountered in severe pre-eclampsia (diastolic blood pressure of greater than 110 mmHg and proteinuria of + + or greater). Furthermore, coagulation abnormality was always associated with a reduced platelet count (mean, 97 x 10(9)/litre). This study would therefore support anaesthetic practice which restricted any requests for coagulation testing to severe pre-eclamptic patients only. For these patients first line testing could be limited to a platelet count.  相似文献   
18.
19.
Femoral and lateral cutaneous nerve of the thigh blocks have been performed in a group of 50 children; the method has not previously been described in paediatric practice. The technique was judged to have been successful in 48 (96%) of the children. There were no early or late complications. It is concluded that these blocks are easy to perform, even in small children and infants, and that they can produce reliable postoperative analgesia for a variety of orthopaedic and plastic procedures.  相似文献   
20.
Laparoscopic pancreatic surgery (LPS) has seen significant development but much of the knowledge refers to small and benign pancreatic tumors. This study aims to evaluate the feasibility, safety, and long-term outcome of the laparoscopic approach in patients with benign, premalignant, and overt malignant lesions of the pancreas. This study, currently, is the largest single center experience worldwide. One hundred twenty-three consecutive patients underwent laparoscopic pancreatic surgery from April 1998 to April 2007, 20 patients with cysts or pseudocysts for acute and chronic pancreatitis, laparoscopic pancreatic drainage was performed, and were excluded from the analysis. The 103 patients were divided based on preoperative diagnosis: group I, inflammatory tumors for chronic pancreatitis (eight patients); group II, cystic pancreatic neoplasms (29 patients); group III, intraductal papillary mucinous neoplasms (10 patients); group IV, neuroendocrine pancreatic tumors (NETs) (43 patients); and group V ductal adenocarcinoma (13 patients). The median tumor size was 5.3 cm. Pathologic data include R 0 or R 1 resection (transection margins on the specimen were inked). Perioperative data, postoperative complications, and resection modalities were compared using statistical analysis. Long-term outcomes were analysed by tumor recurrence and patient survival. The overall conversion rate was 7%. Laparoscopic distal pancreatic resection was performed in 82 patients (79.6%). Laparoscopic spleen-preserving distal pancreatectomy (Lap SPDP) was performed in 52 patients (63.7%), but with splenic vessels preservation in 22% and without splenic vessels preservation in 41.5%. Laparoscopic en-bloc splenopancreatectomy (Lap SxDP) was performed in 30 patients (36.6%) and laparoscopic enucleation (Lap En) in 20 patients (19.4%). There was no mortality. The overall complication rate was 25.2, 16.7, and 40% after Lap SPDP, Lap SxDP, and Lap En, respectively. The overall morbidity rate was significantly higher (p > 0.05) in the group of Lap SPDP without splenic vessels preservation comparing with Lap SPDP with splenic vessels preservation because of the occurrence of splenic complications (20.6%). The overall pancreatic fistulas was 7.7, 10, and 35% after Lap SPDP, Lap SxDP, and Lap En, respectively; the severity of fistula was significantly higher in the Lap En group (p > 0.05). The mean hospital stay was within 1 week in all groups, except in the group of ductal adenocarcinoma, which is 8 days. In this series, 27 patients (26.2%) had malignant disease. R 0 resection was achieved in 90% of ductal adenocarcinoma and 100% for other malignant tumors. The median survival for ductal adenocarcinoma patients was 14 months. This series demonstrates that LPS is feasible and safe in benign-appearing and malignant lesions of the pancreas.  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