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   3213篇
  免费   195篇
  国内免费   79篇
耳鼻咽喉   41篇
儿科学   180篇
妇产科学   55篇
基础医学   397篇
口腔科学   35篇
临床医学   298篇
内科学   823篇
皮肤病学   52篇
神经病学   211篇
特种医学   345篇
外科学   246篇
综合类   70篇
预防医学   219篇
眼科学   115篇
药学   308篇
中国医学   4篇
肿瘤学   88篇
  2022年   28篇
  2021年   50篇
  2020年   35篇
  2019年   37篇
  2018年   64篇
  2017年   40篇
  2016年   57篇
  2015年   48篇
  2014年   86篇
  2013年   114篇
  2012年   141篇
  2011年   155篇
  2010年   102篇
  2009年   114篇
  2008年   138篇
  2007年   180篇
  2006年   156篇
  2005年   152篇
  2004年   133篇
  2003年   107篇
  2002年   104篇
  2001年   96篇
  2000年   120篇
  1999年   92篇
  1998年   83篇
  1997年   83篇
  1996年   77篇
  1995年   76篇
  1994年   42篇
  1993年   54篇
  1992年   48篇
  1991年   56篇
  1990年   55篇
  1989年   72篇
  1988年   67篇
  1987年   60篇
  1986年   54篇
  1985年   50篇
  1984年   41篇
  1983年   15篇
  1982年   23篇
  1981年   23篇
  1980年   26篇
  1979年   18篇
  1978年   12篇
  1977年   16篇
  1976年   14篇
  1975年   16篇
  1974年   9篇
  1972年   7篇
排序方式: 共有3487条查询结果,搜索用时 27 毫秒
1.
2.
3.
Osteoporosis is a chronic and potentially debilitating disease. A painful consequence of osteoporosis is a compression fracture of a vertebral body of the spine. These fractures can lead to physical deformities and emotional trauma. Treatment options for these fractures are limited and occasionally ineffective. New surgical advances in treating vertebro-compression fractures are evolving. Kyphoplasty is a new surgical procedure now being used to treat the painful compression fracture.  相似文献   
4.
5.
1. Fifty-five intact and six baroreceptor denervated and vagotomized cats of either sex were anaesthetized intraperito-neally with urethane (400 mg/kg) and a-chloralose (40 mg/kg). Responses of the systemic arterial pressure (SAP), mean SAP (MSAP) and sympathetic vertebral nerve (VNA) and renal nerve activities (RNA) were recorded. 2. In intact animals, monosodium L-glutamate (Glu, 0.1 mol/L, 50 nL) was microinjected into pressor areas of the locus coeruleus (LC), gigantocellular tegmental field (GTF), rostral ventrolateral medulla (RVLM) and dorsomedial medulla (DM), and the depressor areas of caudal ventrolateral medulla (CVLM). The induced actions were compared before and after microinjection of either glutamate antagonists, glutamate diethylester (GDEE, 0.5 mol/L, 50–100nL), a competitive AMPA receptor blocker, or 2-amino-5-phosphonovaleric acid (D-AP5, 0.025 mol/L, 50–100 nL), a competitive N-methyl-D-aspartate (NMDA) receptor blocker. GDEE completely blocked the increases of SAP and VNA elicited from all pressor areas. D-AP5 only partially blocked the pressor but slightly blocked VNA and RNA responses from LC, GTF and DM, particularly those from RVLM. Neither GDEE nor D-AP5 blocked the depressor responses of SAP and two nerve activities elicited from CVLM. 3. In baroreceptor denervated animals, NMDA (2 mmol/L, 50–100 nL) and AMPA (0.2 mmol/L, 50–100 nL) were micro-injected into the same pressor areas of GTF, RVLM and DM and the depressor area of CVLM responsive to Glu activation (0.1 mol/L, 30 nL). In RVLM, DM and CVLM, the results of either NMDA or AMPA were similar to those induced by Glu. However, in GTF, microinjection of either NMDA or AMPA did not induce similar responses to Glu. This suggests that the nature of GTF may differ from RVLM and DM. 4. The above results suggest that the Glu-induced pressor responses from LC, GTF, DM and especially RVLM, are primarily mediated through AMPA receptors. The Glu-induced depressor responses from CVLM may not be predominantly mediated by either AMPA or NMDA receptors. 5. In both baroreceptor-intact and -denervated cats stimulation of the pressor areas often produced an increase of VNA and a decrease of RNA, while in the depressor CVLM decreased both VNA and RNA. The VNA, but not RNA were positively correlated with the pressor responses, while both VNA and RNA were positively correlated with the depressor responses. This may suggest that neurons of the sympathetic vertebral and renal nerves are topographically organized in the brain.  相似文献   
6.
Cast syndrome     
The term cast syndrome is used to denote duodenal obstruction occurring after application of a corrective plaster cast to patients with scoliosis. We report a classical case in a 14-year-old female who required surgical intervention after conservative treatment failed. Six months later the patient had no further gastrointestinal symptoms. Clinical, radiological, and pathological details as well as the surgical treatment are described and discussed. Offprint requests to: M. E. Martín Hortigüela  相似文献   
7.
Proximal femoral focal deficiency, an uncommon congenital anomaly, necessitates early radiologic classification for surgical planning and treatment. Objective radiographic criteria, including femoral length index, acetabular depth index, acetabular angle index, and shape of the proximal femur were determined in 49 patients before cartilaginous ossification of the femoral capital epiphysis; final classification was based on follow-up radiographs or findings at arthrography or surgery. These parameters were analyzed to determine the accuracy and contributions of each in classification. Correct classification into one of three groups was possible in 86% of cases with use of three of the parameters: femoral length index, acetabular depth index, and shape of the proximal femur. The acetabular angle was found to contribute insignificantly to classification. Magnetic resonance imaging, used in only one case, depicted the nonossified cartilaginous femoral capital epiphysis, thus obviating the need for invasive diagnostic procedures and facilitating early classification.  相似文献   
8.
This study investigated the extent of impairment in functional parameters of liver mitochondria from rats treated for 60 days with hexachlorobenzene (HCB). A constant amount of mitochondrial uncoupling was found throughout the treatment period. At the same time a nearly constant amount of pentachlorophenol was detected in these mitochondria. In contrast, the level of mitochondrial porphyrins increased progressively. There was good correlation between the concentration of mitochondrial pentachlorophenol and the degree of uncoupling of oxidative phosphorylation.  相似文献   
9.
10.
High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.   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