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   1622篇
  免费   106篇
  国内免费   22篇
耳鼻咽喉   1篇
儿科学   151篇
妇产科学   19篇
基础医学   182篇
口腔科学   47篇
临床医学   157篇
内科学   366篇
皮肤病学   24篇
神经病学   32篇
特种医学   470篇
外科学   100篇
综合类   28篇
预防医学   46篇
眼科学   14篇
药学   51篇
中国医学   3篇
肿瘤学   59篇
  2022年   4篇
  2021年   7篇
  2020年   9篇
  2019年   7篇
  2018年   16篇
  2017年   10篇
  2016年   22篇
  2015年   27篇
  2014年   26篇
  2013年   56篇
  2012年   21篇
  2011年   21篇
  2010年   72篇
  2009年   56篇
  2008年   33篇
  2007年   24篇
  2006年   29篇
  2005年   20篇
  2004年   14篇
  2003年   15篇
  2002年   19篇
  2001年   13篇
  2000年   23篇
  1999年   25篇
  1998年   133篇
  1997年   118篇
  1996年   124篇
  1995年   91篇
  1994年   74篇
  1993年   83篇
  1992年   25篇
  1991年   28篇
  1990年   16篇
  1989年   60篇
  1988年   44篇
  1987年   49篇
  1986年   45篇
  1985年   47篇
  1984年   24篇
  1983年   31篇
  1982年   34篇
  1981年   20篇
  1980年   36篇
  1979年   14篇
  1978年   15篇
  1977年   17篇
  1976年   23篇
  1975年   24篇
  1971年   2篇
  1966年   2篇
排序方式: 共有1750条查询结果,搜索用时 27 毫秒
991.
L Carr  JA Pryor  ME Hodson 《Physiotherapy》1995,81(12):753-757
The literature suggests that self chest clapping (SCC) does not enhance rate of sputum clearance if combined with the active cycle of breathing techniques (ACBT), but many patients find SCC beneficial and continue to use it. Previous studies have examined the effects of assisted chest clapping on oxygen saturation (SaO2), but what would be the effects of SCC on SaO2? It was important to establish any possible detrimental effects from its use and to explore the views of patients using it as part of their treatment.

The SaO2 was measured in 20 clinically stable patients with cystic fibrosis during their physiotherapy (the ACBT with SCC in a gravity assisted position) and all patients completed a short anonymous questionnaire to obtain their views on SCC. Patient characteristics of lung function, arterial blood gases, response to bronchodilator therapy, 24-hour sputum weight and exercise ability were recorded, within 48 hours of participation within the study, to identify a possible relationship between these and a change in SaO2.

In the group as a whole there was a statistically significant mean fall in SaO2 with SCC (p = 0.026). However, this fall was never greater than 4.4%. In some patients a fall in SaO2 was recorded with SCC, but in others there was an increase. There was no correlation between the variables measured and a fall in SaO2 with SCC. The patients using SCC had strong views and beliefs about why they did so.  相似文献   

992.
The pathophysiology and clinical relevance of platelet heterogeneity   总被引:5,自引:0,他引:5  
Thompson  CB; Jakubowski  JA 《Blood》1988,72(1):1-8
Recent studies on platelet heterogeneity support the hypothesis that platelet production is regulated to maintain a constant functional platelet mass. In concept this form of regulation is analogous to the manner by which RBC production is controlled to maintain the oxygen- carrying capacity of blood. The platelet mass appears to correlate more closely with platelet function than the platelet count alone, since several factors in addition to the platelet count have been shown to influence the platelets' hemostatic function. These factors include platelet size, density, age, and previous hemostatic interactions. Application of these concepts to clinical problems has provided important insights into platelet physiology and reactivity. Failure to account for differences in platelet heterogeneity among individuals may introduce significant errors in the interpretation of data from laboratory and clinical investigations. However, despite advances, a number of practical issues remain to be resolved before measurements of platelet heterogeneity become accepted as routine clinical tests and are used in the diagnosis of pathologic states.  相似文献   
993.

Background  

The relevance of angiogenesis inhibition in the treatment of glioblastoma multiforme (GBM) should be considered in the unique context of malignant brain tumours. Although patients benefit greatly from reduced cerebral oedema and intracranial pressure, this important clinical improvement on its own may not be considered as an anti-tumour effect.  相似文献   
994.
995.
996.
Cystic fibrosis (CF) is relatively common, serious, and causes progressive lung damage. Clinical diagnosis may be delayed until lung damage has occurred, and infection may start as early as six weeks of life. A well organised screening programme should identify the great majority of affected infants within the first three weeks after birth, which leaves a small time window during which effective preventive treatment and surveillance may be instituted. Active treatment, whether for screened or unscreened infants, improves clinical status and long-term survival of CF patients. It is anticipated that new treatments will become available within the next few years, and these will clearly give maximal benefit to young infants if instituted before lung damage is evident. In addition to any hypothetical effects on morbidity and survival, pre-symptomatic diagnosis greatly improves the doctor-parent relationship. Economic arguments may be distorted, but, at best, screening is cost-beneficial, and, at worst, it is cost-neutral. The overwhelming majority of CF professionals and parents universally support neonatal screening, so the onus is therefore on those who oppose screening to prove that their approach offers a superior strategy.  相似文献   
997.
Intrahepatic interruption of the inferior vena cava is a congenital anomaly, resulting in venous drainage of the lower extremities by way of a compensatory enlarged vena azygos system. We report the case of a 37-year-old male who presented with symptoms of deep vein thrombosis of the entire right lower extremity. A right-sided mediastinal mass on the chest X-ray was mistaken for a haematological malignancy but proved later to represent an enlarged azygos vein. The case illustrates that in a case of deep vein thrombosis, especially in younger patients, interruption of the inferior vena cava should be considered. A right-sided paratracheal mass on the chest X-ray may give a clue in making the correct diagnosis.  相似文献   
998.
999.
We report a case of renal capsular artery pseudoaneurysm caused by percutaneous renal biopsy. The injury was diagnosed and treated with arteriography and transarterial embolization. Because the arterial injury was extraparenchymal, the clinical manifestations of blood loss were flank pain and decreasing hematocrit without hematuria. Injury to renal capsular arteries during percutaneous renal biopsy is a rare possibility because of their small size.  相似文献   
1000.
目的分析创伤性动静脉瘘(AVF)的临床特点、造影表现、造影技术及治疗方式的选择。方法回顾性分析纽约Kings County医疗中心25年间全部确诊的108例创伤性AVF的介入相关诊疗资料。分析内容包括患者外伤种类、临床表现、损伤部位、血管造影异常特征、AVF血流动力学特征(分5个类型)、治疗方式的选择等。结果 108例患者中共发现117处AVF,大多数患者临床特征不明确。创伤种类包括枪伤(导致72处AVF)、刺伤(24处)、钝性伤(8处)、高处坠落伤(3处)、医源性损伤(2处)。损伤部位常见于肢体(46例)、颈部(19例)、肝脏(13例)和锁骨下血管(11例)。所有病变均可见静脉早显,显示动脉横断52处,撕裂37处,49.6%的AVF与假性动脉瘤有关。最常见的血流特点是Ⅰ型,即瘘口所在的动脉近段和远段、静脉的近段和远段都显示,伴远侧段静脉瓣功能不全,共40处瘘(34.2%),其次是Ⅲ型22个(18.8%),Ⅴ型最不常见(4.3%)。34例接受手术治疗,61例栓塞治疗,7例临床观察。分别采用弹簧圈(47例)、明胶海绵(9例)、无水乙醇(3例)、可脱球囊(2例),其中弹簧圈效果理想、并发症少。6例采用覆膜支架效果好。结论血管造影是诊断创伤性AVF的金标准,造影时准确观察动脉损伤的性质,瘘口的解剖和血流特点及所有进入瘘口的动脉分支,对于选择治疗方式及保证介入治疗的成功完成至关重要。  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