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   38921篇
  免费   3046篇
  国内免费   788篇
耳鼻咽喉   187篇
儿科学   703篇
妇产科学   794篇
基础医学   2164篇
口腔科学   1444篇
临床医学   11516篇
内科学   2935篇
皮肤病学   172篇
神经病学   3565篇
特种医学   1519篇
外国民族医学   5篇
外科学   6743篇
综合类   3382篇
一般理论   4篇
预防医学   1481篇
眼科学   111篇
药学   2948篇
  57篇
中国医学   1999篇
肿瘤学   1026篇
  2024年   132篇
  2023年   957篇
  2022年   1437篇
  2021年   2020篇
  2020年   1975篇
  2019年   1940篇
  2018年   1826篇
  2017年   1762篇
  2016年   1544篇
  2015年   1486篇
  2014年   2874篇
  2013年   3467篇
  2012年   2032篇
  2011年   2266篇
  2010年   1827篇
  2009年   1693篇
  2008年   1883篇
  2007年   1644篇
  2006年   1502篇
  2005年   1171篇
  2004年   1027篇
  2003年   859篇
  2002年   723篇
  2001年   624篇
  2000年   483篇
  1999年   489篇
  1998年   393篇
  1997年   366篇
  1996年   289篇
  1995年   261篇
  1994年   244篇
  1993年   195篇
  1992年   195篇
  1991年   144篇
  1990年   101篇
  1989年   104篇
  1988年   90篇
  1987年   98篇
  1986年   93篇
  1985年   105篇
  1984年   83篇
  1983年   61篇
  1982年   71篇
  1981年   62篇
  1980年   50篇
  1979年   30篇
  1978年   18篇
  1977年   14篇
  1976年   20篇
  1975年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
BACKGROUND: Our objective was to determine the cost-effectiveness of a comprehensive, risk-based triage system, composed of multiple critical pathways, with the use of early myocardial perfusion imaging (MPI) in low-risk patients. We found previously that a chest pain evaluation system that uses MPI in low-risk patients was safe and effective, but the cost-effectiveness of this approach was not studied. METHODS AND RESULTS: We compared two groups. The Acute Cardiac Team (ACT) group (n = 874) was assigned prospectively to 1 of 4 risk levels by emergency department (ED) physicians. Level 1, 2, and 3 patients were admitted; level 4 patients were evaluated in the ED. Level 3 and 4 patients underwent ED MPI. The control group (n = 713) represented consecutive patients evaluated in the prior year according to standard care and assigned retrospectively to an ACT level based on the presenting electrocardiographic and clinical data. Record and hospital administrative data were assessed for clinical variables, outcomes, lengths of stay, and all expenses incurred within 30 days of the index visit. The baseline characteristics of the two groups were similar, including age, sex, myocardial infarction prevalence, and 30-day revascularization rates within each level or between the two groups. Mean costs per encounter were reduced for the ACT patients for each level, which was significant when all patients were compared ($5,030 +/- $7,081 vs $6,044 +/- $10,432, P =.02). Use of MPI in the low-risk patients was associated with reduced costs (level 3, $4,958 +/- $4,948 vs $5,051 +/- $7,036; level 4, $1,529 +/- $2,664 vs $1,794 +/- $6,854) and was associated with a significantly lower angiography rate and shorter length of stay. CONCLUSIONS: Implementation of a comprehensive strategy for chest pain evaluation and triage reduced overall costs for patients with chest pain on presentation. Acute MPI in the ED setting did not increase net cost.  相似文献   
52.
13例有心绞痛样胸痛的住院病人入院均诊有冠心病心绞痛,后均经ECG、8例心脏“B”超、核素心肌灌注及24小时动态ECG各2例,确诊冠心病5例,不支持冠心病8例;后均行GI,并同时行胃镜、食管24小时pH测定及压力测定各2例,确诊有胃食管反流疾病(GERD),本组自胸痛症状出现至GERD确诊病程平均29.5个月(0.5~120个月),报告2例典型病例,讨论了误漏诊原因,探讨了老年人食管性胸痛的诊疗程序。  相似文献   
53.
刺激视上核对大鼠痛阈及电针镇痛的影响   总被引:2,自引:1,他引:1  
以钾离子透引起的大鼠甩尾反应为痛指标,观察了电和化学刺激视上核(SON)对大鼠痛阈(PT)和电针(EA)镇痛的影响。电刺激SON后,PT明显高于假刺激组(P<0.05~0.001),电刺激SON后电针足三里,镇痛效应明显提高,并有明显的量效关系。电刺激SON的近旁部位(0.5—1mm)对PT及电针镇痛无明显影响。SON内注射L-谷氨酸(L-Glu)后痛阈和电针镇痛效应都明显对照组,也有明显的量效关  相似文献   
54.
Summary In the last decades back pain has reached dramatic proportions in industrialized countries. Disorders of the back are nowadays the leading cause of direct and indirect health care costs. Accurate prevalence estimates are needed to serve as a basis for health care evaluations. A review of epidemiologic studies in the general population reveals that back pain has reached a prevalence of 40 % for current pain. 7 to 18 % are “frequently”, “often”, “daily” or “constantly” affected. 75 % of the adult population suffers from back pain during the last year. 80 to 90 % of the adult population in industrialized countries experience back pain ever. Gender specific differences are only present in severe, chronic forms which are more often experienced by women. Back pain has a prevalence maximum at 50 to 64 years. Older persons display lower prevalence estimates. The prevalence maximum in men is one decade earlier than in women. There are several potential explanations for this prevalence pattern that are discussed in the article. Back pain can be classified by location, temporal characteristics, pain intensity and pain history. Currently, for none of these dimensions generally accepted, uniformly employed and validated definitions are available. In most of the industrialized countries back pain is one of the most expensive symptoms. 75–90 % of the direct and indirect health care costs were caused by those 5–10 % of patients who are disabled. As predictors of back pain a history of back pain and job satisfaction play by far a more important role than the extensively studied mechanical factors. For a first episode of back pain the prognosis is favorable. If the pain persist for more than three months the prognosis is unfavorable. After six months of absenteeism because of back pain more than half of the afflicted never return to work. Rarely back pain is present as a single symptom. In more than 80 % back pain is associated with pain in at least one joint. It remains to be studied if back pain may be viewed as an entity or as part of a more complex pain syndrome.   相似文献   
55.
56.
无张力疝修补术后顽固性疼痛原因和对策   总被引:1,自引:0,他引:1  
目的 探讨无张力疝修补术后的顽固性疼痛病因及预防治疗。方法 将同期无张力疝修补术与传统的腹股沟疝修补方法进行比较。结果 无张力疝修补术后的顽固性疼痛率为9.02%(12/133),传统的腹股沟疝修补方法疼痛率为8.61%(18/209)。无张力疝修补与传统的腹股沟疝修补相比,术后顽固性疼痛的发生率差异无显著性(P>0.05)。结论 无张力疝修补并不一定减少传统的腹股沟疝修补术后顽固性疼痛,手术规范操作是预防的关键,治疗应先保守治疗,无效再考虑手术治疗。  相似文献   
57.
58.
Solid customized and prefabricated silicone implants have been used by the author for 15 years in a wide range of chest wall deformities. Chest wall implants are often used in males seeking to augment a muscularly deficient or underdeveloped chest; however, their greatest use has come in a variety of deformities both congenital and acquired, such as pectus excavatum, Poland's Syndrome, and pectoralis muscle tears. The implants can be either customized using a moulage technique or are prefabricated, manufactured implants which can be modified on the operating table to repair the contour deformity. The immediate postoperative problem of seroma and subcutaneous implant ``show' has been minimized by careful planning, gentle technique, deep insertion, improved patient positioning on the operating room table, and the use of oral anti-inflammatory medications. The long-term results of these implants seem very satisfactory. The patients are usualy physically active, and the implants show no long-term sequelae such as seroma, infection, displacement, or rupture.  相似文献   
59.
Congenital analgesia is a rare genetic disorder. We report here that a 12-year-old boy was able to recover from congenital insensitivity to pain. Neurological examinations revealed that there was a 'stocking' distribution of pain decrement on the lower extremities under the patient's knee joints. Magnetic Resonance Imaging (MRI) of his brain showed gyrus thinning with sulcus widening at both sides of the parietal lobe. Southern blot hybridization probed with cDNAs of various opioid receptors did not detect any significant abnormality. Our results suggest that this rare case may not be genetically determined.  相似文献   
60.
Survey of postoperative analgesia following ambulatory surgery   总被引:4,自引:0,他引:4  
Background: The quality of pain relief during the first 48 hours following ambulatory surgery has been poorly documented. This questionnaire study was performed to evaluate the nature and severity of pain after the patient leaves the hospital. Methods: 1100 patients in the age group 5–88 years who underwent ambulatory surgery during a period of 6months were asked to complete a questionnaire 48 h after the end of the operation. In thecase of children, parents were asked to complete a similar questionnaire. The questions were related to pain experienced during the first 48 h after surgery and to the nature andseverity of postoperative complications. Results: A total of 1035 out of the 1100 patients returned the questionnaire, 94.1%. Overall the majority (65%) of patients had only mild pain at home; however, patients undergoing certain types of surgery had moderate-to-severe pain: inguinal hernia surgery (62% patients), orthopaedic surgery (41%), hand surgery (37%) and varicose vein surgery (36%). In these patients the severity of pain did not decrease during the 2-day study period. About 10% patients had more severe pain than they had anticipated, and 20% had difficulty in sleeping at night due to severe pain. Despite this, over 95% of patients were satisfied with man-agement of postoperative pain. Nausea (20%), tiredness (20%) and vomiting (8%) were the commonest complications reported during the first 48 h. A significant association was found between the administration of a general anaesthetic and the incidence of nausea postoperatively. A large number of patients were alone at home after the operation (28.4%); some (3.8%) had no access to a relative or friend in case of need. Conclusion: Our results show that about 35% of day-surgery patients experience moderate-to-severe pain at home in spite of analgesic medication. About 20% of patients had sleep problems due to severe pain. However, only 5% of patients were dissatisfied. Better analgesic techniques are necessary for patients undergoing certain types of surgery. Patient information and follow-up routines need to be improved.  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