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   1613篇
  免费   122篇
  国内免费   19篇
耳鼻咽喉   4篇
儿科学   103篇
妇产科学   10篇
基础医学   167篇
口腔科学   94篇
临床医学   163篇
内科学   308篇
皮肤病学   63篇
神经病学   84篇
特种医学   248篇
外科学   193篇
综合类   41篇
一般理论   1篇
预防医学   83篇
眼科学   41篇
药学   68篇
  1篇
中国医学   3篇
肿瘤学   79篇
  2023年   8篇
  2022年   26篇
  2021年   37篇
  2020年   17篇
  2019年   21篇
  2018年   28篇
  2017年   19篇
  2016年   26篇
  2015年   39篇
  2014年   45篇
  2013年   67篇
  2012年   68篇
  2011年   50篇
  2010年   79篇
  2009年   76篇
  2008年   49篇
  2007年   63篇
  2006年   52篇
  2005年   48篇
  2004年   36篇
  2003年   47篇
  2002年   46篇
  2001年   29篇
  2000年   13篇
  1999年   37篇
  1998年   86篇
  1997年   82篇
  1996年   65篇
  1995年   56篇
  1994年   42篇
  1993年   48篇
  1992年   17篇
  1991年   36篇
  1990年   25篇
  1989年   46篇
  1988年   36篇
  1987年   29篇
  1986年   20篇
  1985年   20篇
  1984年   10篇
  1983年   12篇
  1982年   15篇
  1981年   15篇
  1980年   15篇
  1979年   3篇
  1978年   14篇
  1977年   11篇
  1976年   10篇
  1975年   8篇
  1946年   1篇
排序方式: 共有1754条查询结果,搜索用时 31 毫秒
991.
Infants and young children may be exposed to a variety of dangerous situations when left sleeping in cots, chairs, or beds. A review of 30 cases of accidental asphyxia occurring in infants and young children who had been left to sleep unattended was undertaken from the necropsy and consultation files of the Adelaide Children's Hospital. Causes of death included hanging from loose restrainers, clothing, or a curtain cord (12 cases), positional asphyxia/wedging from slipping between a mattress and bed/cot sides or wall, or from moving into a position where the face was covered and the upper airway occluded (16 cases), and suffocation from plastic bed covers (two cases). Cases of co-sleeping in bed with an adult and of non-accidental asphyxia were not included in this review. As the pathological findings were on occasion identical to those that are typically found in sudden infant death syndrome, adequate death scene examination was vital in several cases to allow identification of lethal sleeping environments and to enable steps to be taken to minimise the risk of future deaths due to similar situations. For example, two cases in which infants asphyxiated in rocking cradles led to the investigation of the cradles and to formulation of specific safety recommendations regarding the angle of tilt. Two infants who died after becoming wedged between the back of a couch and a co-sleeping parent in one case and cushions in the other, would indicate that this also represents a potentially lethal sleeping position. Other dangerous situations involved infant car seat restraints, seats with loose harnesses, cots with movable sides or projecting pieces, thin plastic mattress/pillow coverings, and beds with spaces between the mattress and cot side or wall. Lack of supervision at the time of death was a feature of each case.  相似文献   
992.
Fifty-three critically ill infants and children received midazolam as sedation in a regional intensive care unit. Assessment of the level of sedation was carried out at regular intervals on withdrawal of midazolam. Forty-nine patients were fully alert within 4 h of midazolam being stopped. Four patients took from 6 h to 1 week to become fully alert. Four patients had abnormal behaviour highly suggestive of midazolam withdrawal. The onset of abnormal behaviour was within 12 h of discontinuation of midazolam. The duration of the abnormal behaviour ranged from 3 h to 1 week. One child had a paradoxical reaction to midazolam. The overall incidence of adverse effects to midazolam in the patients studied was 17%. No adverse effects were observed in infants; all adverse effects were observed in children. We have shown that it is possible to prospectively study the toxicity of sedatives in critically ill infants and children.  相似文献   
993.
AIM. To investigate whether the extent of ocular morbidity had de-creased as a result of improved diagnosis, awareness and treatment of Wegener 's granulomatosis (WG). MATERIALS AND METHODS. A retrospective study of all patients with ophthalmic involvement due to WG over an 8-year period. RESULTS. Forty-nine patients were diagnosed to have WG. Of these, 28 had ocular involvement: 21 patients had focal ocular involvement (conjunctivitis, episcleritis, scleritis, keratitis, iritis, retinitis)and 7 had orbital involvement. Permanent visual loss occurred in three patients with orbital involvement, but in no patients with focal ocular disease. Up to 90% of patients had systemic involvement. Three deaths oc- curred among those with ocular involvement. CONCLUSIONS. Patients with WG have a much improved visual prog- nosis as a result of early diagnosis and intervention with systemic im- munosuppression. A combination of assays for ANCA and tissue biop-sies were needed to establish the diagnosis of WG. Treatment with immunosuppressive agents (usually prednisolone and cyclophospha- mide)led to a good response in the majority of cases.  相似文献   
994.
Caro  J; Erslev  AJ; Silver  R; Miller  O; Birgegard  G 《Blood》1982,60(4):984-988
Erythropoietin production in response to hypoxic-hypoxia is markedly reduced in the newborn when compared to the adult rat. This response improves steadily with age and reaches adult values at about 4 wk. When animals of the same age are stimulated with anemic-hypoxia, considerably higher levels of erythropoietin are found. The erythropoietin level is proportional to the degree of anemia and independent of the age of the animal. Extraction of erythropoietin from tissue homogenates revealed a parallelism between the plasma and kidney erythropoietin content, while no erythropoietin could be extracted from liver tissue at any age. The lack of response to hypoxia in the newborn appears to be related to the high hemoglobin oxygen affinity during the neonatal period, which facilitates oxygen loading. Newborn rats have a very low intraerythrocytic concentration of 2-3 DPG and a marked shift to the left in the oxygen hemoglobin dissociation curve that slowly increases to adult values at 4 wk of age. The response to anemia on the other hand, appears to be normal and not affected by age or by hemoglobin oxygen affinity. These studies suggest that the newborn rat, when properly stimulated, is able to produce normal amounts of erythropoietin, most likely renal in origin.  相似文献   
995.
996.
997.
Summary The authors report a rare case of cranial and intracranial mycetoma which presented with occipital sinuses, extensive involvement of skull vault and base, an extradural granuloma and intracranial hypertension. Radiological appearances are reviewed. The computerized tomography findings are the first of their kind for this condition. The diagnosis and treatment of this disease are discussed.  相似文献   
998.
Idiopathic hypertrophic osteoarthropathy without pachyderma   总被引:1,自引:0,他引:1  
  相似文献   
999.
1000.
Seven normal knees (in five volunteers) and seven injured knees (in seven patients) were examined by high-resolution magnetic resonance (MR) imaging at 1.5 T with a surface coil. Seven medial meniscal tears, three anterior cruciate ligament tears, one posterior cruciate ligament avulsion, an old osteochondral fracture, femoral condylar chondromalacia, and one case of semimembranous tendon reinsertion were identified. MR images correlated well with recent double-contrast arthrograms or results of surgery. All tears were identified in both the sagittal and coronal planes. Because of its ability to demonstrate small meniscal lesions and ligamentous injuries readily, MR imaging with a surface coil may eventually replace the more invasive arthrography.  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