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   5036篇
  免费   428篇
  国内免费   34篇
耳鼻咽喉   82篇
儿科学   121篇
妇产科学   106篇
基础医学   547篇
口腔科学   255篇
临床医学   543篇
内科学   1044篇
皮肤病学   108篇
神经病学   349篇
特种医学   337篇
外国民族医学   1篇
外科学   746篇
综合类   105篇
一般理论   4篇
预防医学   341篇
眼科学   102篇
药学   244篇
中国医学   5篇
肿瘤学   458篇
  2018年   54篇
  2016年   51篇
  2015年   48篇
  2014年   68篇
  2013年   110篇
  2012年   150篇
  2011年   171篇
  2010年   110篇
  2009年   96篇
  2008年   173篇
  2007年   215篇
  2006年   207篇
  2005年   186篇
  2004年   171篇
  2003年   186篇
  2002年   187篇
  2001年   175篇
  2000年   184篇
  1999年   149篇
  1998年   72篇
  1997年   68篇
  1996年   61篇
  1995年   58篇
  1994年   64篇
  1993年   55篇
  1992年   127篇
  1991年   142篇
  1990年   114篇
  1989年   128篇
  1988年   142篇
  1987年   134篇
  1986年   121篇
  1985年   147篇
  1984年   92篇
  1983年   98篇
  1982年   69篇
  1981年   61篇
  1980年   45篇
  1979年   85篇
  1978年   75篇
  1977年   61篇
  1976年   74篇
  1975年   51篇
  1974年   55篇
  1973年   58篇
  1972年   52篇
  1971年   52篇
  1970年   50篇
  1969年   45篇
  1968年   41篇
排序方式: 共有5498条查询结果,搜索用时 15 毫秒
1.
2.
We treated 100 consecutive ureteral calculi requiring intervention with a previously described algorithm. There were 16 ureteropelvic junction, and 18 upper, 22 mid and 44 lower ureteral calculi. Treatment was by a stent and extracorporeal shock wave lithotripsy in 10 ureteropelvic junction, 10 upper ureteral and 3 mid ureteral calculi, ureteroscopy and extracorporeal shock wave lithotripsy in 6 upper and 6 mid ureteral calculi, and ureteroscopy alone in 5 ureteropelvic junction, 2 upper and 12 mid ureteral calculi. All 44 lower ureteral calculi were treated successfully by ureteroscopy. Of the 100 patients studied 98 were treated by endourological methods (extracorporeal shock wave lithotripsy or ureteroscopy), while 2 required an operation (1 with a ureteropelvic junction calculus and 1 with a mid ureteral calculus). Over-all, 100 patients required a total of 125 procedures to accomplish successful stone removal. An algorithm is developed in which lower ureteral calculi are treated by ureteroscopy, mid ureteral calculi (large and dense) by stent bypass and extracorporeal shock wave lithotripsy or (lucent and fragile) by ureteroscopy, upper ureteral calculi by stent bypass and extracorporeal shock wave lithotripsy without manipulation, and impacted ureteral stones initially by ureteroscopy and, if necessary, then by extracorporeal shock wave lithotripsy.  相似文献   
3.
4.
5.
A new method for producing temporary complete cerebral ischemia in rats   总被引:2,自引:0,他引:2  
A new model of temporary complete cerebral ischemia was developed and tested in 64 rats. With use of microsurgical techniques, both pterygopalatine and external carotid arteries were occluded and the basilar artery was coagulated to reduce potential collateral CBF during ischemia. After this preliminary five-vessel occlusion, temporary global ischemia was induced by occluding the common carotid arteries (CCAs) with microclips. To validate the method, CBF was measured autoradiographically in 24 anatomical regions at death after 5 min of ischemia or after 15 min of ischemia followed by 5 min of reperfusion. Mean arterial blood pressure and arterial blood gases remained stable under controlled endotracheal ventilation and anesthesia (halothane, 70% N2O, and 30% O2) throughout the CBF experiments, except for a 10-15% increase in mean arterial blood pressure for 1-5 min after bilateral CCA occlusion. After the initial five-vessel occlusion, the EEG did not change, and local CBF levels were comparable to those in anesthetized non-surgical controls. When the CCAs were occluded, the EEG flattened rapidly; after 5 min of ischemia, autoradiography showed no detectable blood flow in the forebrain and cerebellum. The local CBF levels measured after 15 min of temporary global ischemia and 5 min of reperfusion demonstrated relatively homogeneous postischemic hyperperfusion; only two of eight rats had several 1- to 3-mm areas of no-reflow. Survival studies showed increasing motor impairment after 10, 15, 30, and 60 min of temporary CCA occlusion. Ischemic neuronal damage was observed histologically in the hippocampus and basal ganglia 24 h after 10 min of temporary ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
6.
7.
8.
9.
Multicystic dysplastic kidney is a common renal anomaly in the newborn. Long-term problems, such as pain, infection, hypertension and neoplasm, although infrequent, have been reported. Acute, life-threatening complications resulting from the size of the affected kidney are rare and emergency nephrectomy has been the only reported effective therapy. We present a case of ultrasound-guided percutaneous cyst decompression used as definitive treatment of respiratory failure associated with multicystic dysplastic kidney.  相似文献   
10.
Summary Neurofibromatosis is sometimes complicated by impaired renal tubular reabsorption of phosphate, hypophosphatemia, and osteomalacia. Hyperparathyroidism has also been reported in patients with neurofibromatosis. When hypercalcemia and elevated levels of parathyroid hormone are found in osteomalacia, however, it may be difficult to determine if the hyperparathyroidism was primary or tertiary. We describe a patient with neurofibromatosis, hypercalcemic hyperparathyroidism, hypophosphatemic osteomalacia, vitamin D deficiency, and clear-cell hyperplasia of all four parathyroid glands. Serial biomechanical, bone biopsy, and densitometric studies confirmed that treatment with ergocalciferol, calcium, and phosphate supplements significantly improved the osteomalacia but caused increased parathyroid overactivity. After subtotal parathyroidectomy, the parathyroid hormone concentration became normal and the bone mineral content increased at the spine and hip, but inappropriate phosphaturia persisted. The findings indicate that hyperparathyroidism, osteomalacia, and vitamin D deficiency adversely affect each other.  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