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   5920篇
  免费   301篇
  国内免费   61篇
耳鼻咽喉   109篇
儿科学   270篇
妇产科学   130篇
基础医学   490篇
口腔科学   239篇
临床医学   538篇
内科学   1352篇
皮肤病学   106篇
神经病学   280篇
特种医学   123篇
外科学   934篇
综合类   400篇
一般理论   4篇
预防医学   403篇
眼科学   188篇
药学   421篇
  1篇
中国医学   75篇
肿瘤学   219篇
  2023年   87篇
  2022年   282篇
  2021年   397篇
  2020年   189篇
  2019年   205篇
  2018年   229篇
  2017年   151篇
  2016年   186篇
  2015年   255篇
  2014年   298篇
  2013年   307篇
  2012年   445篇
  2011年   415篇
  2010年   253篇
  2009年   220篇
  2008年   325篇
  2007年   301篇
  2006年   312篇
  2005年   304篇
  2004年   237篇
  2003年   244篇
  2002年   178篇
  2001年   52篇
  2000年   55篇
  1999年   36篇
  1998年   33篇
  1997年   25篇
  1996年   27篇
  1995年   13篇
  1994年   15篇
  1993年   8篇
  1992年   23篇
  1991年   18篇
  1990年   19篇
  1989年   13篇
  1988年   17篇
  1987年   14篇
  1986年   5篇
  1985年   11篇
  1984年   6篇
  1983年   6篇
  1981年   6篇
  1980年   6篇
  1979年   5篇
  1977年   6篇
  1974年   6篇
  1973年   4篇
  1972年   4篇
  1970年   5篇
  1969年   4篇
排序方式: 共有6282条查询结果,搜索用时 15 毫秒
61.
目的观察尼可地尔预先给药对心肌缺血再灌注兔心肌细胞凋亡的影响。方法 雄 性新西兰白兔40只,随机分为5组(n=8),假手术组(Sham组):仅穿线,不结扎;IR组:缺血30 min再 灌注120min;Nic组:缺血前10min静脉注射尼可地尔100μg·kg-1负荷量,随后以10μg·kg-1·min-1的 速率持续静脉输注至缺血前即刻;Nic 5-HD、Nic Gli组:在缺血前20 min静脉注射五羧基葵酸钠或 格列本脲5 mg·kg-1,其余的处理同Nic组。再灌注120 min时处死兔,计算心肌梗塞面积,通过两种染 色方法检测心肌细胞凋亡情况,观察心肌超微结构改变,并用免疫组织化学方法测定活化的caspase-3 蛋白表达。结果与IR组比较,Nic组心肌梗塞面积减小,早期凋亡细胞数减少,活化的caspase-3蛋 白表达下降(P<0.05),与Sham组比较,Nic组心肌仍有一定损伤,但较IR组明显改善。与Nic组比 较,Nic 5-HD、Nic Gli组心肌梗塞面积、早期凋亡细胞数、活化的caspase-3蛋白表达增加(P< 0.05)。结论尼可地尔预先给药对缺心肌血再灌注损伤有一定的保护作用,主要通过开放mito-KATPC 及下调活化的caspase-3蛋白的表达。  相似文献   
62.
Methods:We retrospectively analyzed the patients who underwent RALRP for localized prostate cancer by a single surgeon in our clinic from January 1, 2009–February 1, 2016. Continence was defined as no leakage or use of a safety pad for minimal leakage. The main outcome measure was continence at postoperative week 1 and months 1, 6, and 12.Results:Between 2009 and 2016, 239 patients underwent RALRP for localized prostate disease. Seventy-four patients underwent a standard approach (group 1), 88 had posterior reconstruction (group 2), and 77 had posterior reconstruction with total anatomic restoration (group 3). After 1 week, 24.3% of the patients in group 1 (18/74), 31.8% in group 2 (28/88), and 45.8% in group 3 (33/72) were continent (P = .02). One month after the surgery, continence rates for groups 1, 2, and 3 were 56.7, 67, and 75%, respectively (0.065). After 6 and 12 months, continence rates for groups 1, 2, and 3 were 72.9 and 87.8%, 81.8 and 89.7%, and 84.7 and 91.6%, respectively (P = .178 and .7484).Conclusion:Anatomic restoration improves continence rates in the early period after RALRP. Even though other parameters were higher in the total restoration group, immediate continence (at 1 week) was significantly better.  相似文献   
63.
The aim of this study was to evaluate the effects of the novel free radical scavenger caffeic acid phenethyl ester (CAPE) on extracorporeal shock wave lithotripsy (ESWL) induced renal impairment. The study was performed using 30 rabbits which were divided into two groups, each exposed to 3,000 shock waves at 18 kV: (1) control group, (2) ESWL+CAPE treated group. Malodialdehyde (MDA), urine N-acetyl--glucosaminidase (NAG) activity, uric acid and white cell counts were used as markers of oxidative stress. Following shock wave exposure there was a significant rise in MDA, NAG and uric acid and white cell counts. CAPE reduced the rise in MDA, NAG, uric acid and white cell counts. Thus CAPE treatment to a great extent prevented the induction of these renal changes. Our results suggest that the antioxidant capacity of the kidney tissue was reduced after ESWL treatment and that the tissue was exposed to oxidant stress. We conclude that CAPE treatment provided significant protection against ESWL induced free radical damage.  相似文献   
64.
Purpose Peritoneal recurrence is not an uncommon cause of death after surgery for gastric cancer, even after surgery with curative intent. This indicates that there is undetected residual disease in the peritoneal cavity. We conducted this study to determine the value of peritoneal and serum carcinoembryonic antigen (CEA) levels and peritoneal washing cytology in predicting the locoregional and distant spread of gastric cancer. Methods We prospectively evaluated 70 consecutive patients with gastric cancer by measuring peritoneal CEA (pCEA) and serum CEA (sCEA) levels and peritoneal washing cytology results, and studying their effect on the histopathologic properties. The effect of the pCEA level on disease-free survival (DFS) and overall survival (OS) was also evaluated in patients treated with curative intent. Results Twenty-one (30%) patients had sCEA levels >10 ng/ml, whereas 25 patients (35.7%) had pCEA levels >10 ng/g protein and 26 patients (37.1%) had positive cytology. The pCEA levels were significantly higher in patients with hepatic metastases (P = 0.034), or serosal (P = 0.028), and peritoneal (P = 0.026) involvement, whereas the sCEA levels were significantly higher only in patients with hepatic metastases (P = 0.04). Similarly, positive cytology was mainly detected in patients with hepatic metastases (P = 0.004). The pCEA levels significantly affected DFS (P = 0.002) and OS (P = 0.01) in 34 patients treated with curative intent. Conclusion Since pCEA levels are more useful for predicting locoregional recurrence, their measurement during surgery may help plan the most appropriate surgical strategy and adjuvant therapy.  相似文献   
65.
During lower extremity amputation, the objective is to provide a functional residual limb that permits maximum patient mobility and independence. Preservation of length of the fore part of the foot using salvageable tissue from the amputated part in young patients prevents equines deformity and revision of amputation to a higher level. This can be achieved using tissue available from the amputated part. The spare part concept in reconstructive surgery should be integrated into the trauma algorithm to avoid additional donor site morbidity. Reported here is a young adult patient with crush injuries to both feet, which resulted in amputations. A fasciocutaneous flap raised from one extremity was used to facilitate transmetatarsal amputation stump length preservation of the other extremity.  相似文献   
66.
Objectives:To explore the changing patterns of long-stay patients (LSP) to improve the utilization of pediatric intensive care units (PICUs) resources.Methods:This is a 2-points cross-sectional study (5 years apart; 2014-2019) conducted among PICUs and SCICUs in Riyadh, Saudi Arabia. Children who have stayed in PICU for more than 21 days were included.Results:Out of the 11 units approached, 10 (90%) agreed to participate. The prevalence of LSP in all these hospitals decreased from 32% (48/150) in 2014 to 23.4% (35/149) in 2019. The length of stay ranged from 22 days to 13.5 years. The majority of LSP had a neuromuscular or cardiac disease and were admitted with respiratory compromise. Ventilator-associated pneumonia was the most prevalent complication (37.5%). The most commonly used resources were mechanical ventilation (93.8%), antibiotics (60.4%), and blood-products transfusions (35.4%). The most common reason for the extended stay was medical reasons (51.1%), followed by a lack of family resources (26.5%) or lack of referral to long-term care facilities (22.4%).Conclusion:A long-stay is associated with significant critical care bed occupancy, complications, and utilization of resources that could be otherwise utilized as surge capacity for critical care services. Decreasing occupancy in this multicenter study deserves further engagement of the healthcare leaders and families to maximize the utilization of resources.  相似文献   
67.
OBJECTIVE: To determine the prevalence of hyperlipidemia among Saudis of both genders in rural and urban communities. METHODS: Selected Saudis in the age group of 30-70 years were studied over a 5-year period between 1995 and 2000 in Saudi Arabia. Data were obtained from history, physical examination, and analysis of fasting plasma lipids. The data were analyzed to classify individuals with hypercholesterolemia (HC) (total cholesterol > or =5.2 mmol/l), and hypertriglyceridemia (HT) (total triglycerides > or =1.69 mmol/l). Logistic regression analysis was performed to provide a risk assessment model and correlation with other coronary artery disease (CAD) risk factors. RESULTS: The number of study samples included in the final analysis was 16,819. The prevalence of HC was 54% with mean cholesterol level of 5.4+/-1.52 mmol/l. Prevalence of HC among males was 54.9% and 53.2% for females, while 53.4% among urban Saudis and 55.3% for rural Saudis. Hypertriglycemia prevalence was 40.3% with mean triglycerides level of 1.8+/-1.29 mmol/l. Males had statistically significant higher HT prevalence of 47.6% compared to 33.7% in females (p<0.0001). CONCLUSION: Hyperlipedimia is reaching higher prevalence rates in KSA. This finding may suggest that CAD will soon be a major health problem. Reduction in obesity by adopting healthier eating habits, and increasing physical activity are of considerable importance to our community.  相似文献   
68.
Glomerulonephritis (GN) is one of the commonest causes of chronic renal failure (CRF) and end stage renal failure (ESRF). The outcome largely depends on the underlying medical cause, clinical findings and histological appearance. 1188 patients were taken in this study. Of these, 980 had primary and 208 secondary GN. Commonest histological types of primary GN were mesangial proliferative glomerulonephritis (31%) and membranous nephropathy (21%). Among patients with secondary GN, predominant cause was lupus nephritis (76%) followed by poststreptococcal GN (18%). Clinically, nephrotic syndrome was present in 54%, hypertension in 39% and renal failure in 28%. But clinical pictures were variable among different histological types of GN.  相似文献   
69.
70.
Objectives:To assess National Institutes of Health Stroke Scale (NIHSS), stroke volume, biochemical, and blood parameters for the prediction of one-month mortality in stroke patientsMethods:The study had retrospective design and 75 patients were involved that presented to a hospital Emergency Department between January 2016 and December 2017 in Adiyaman, Turkey diagnosed with acute ischemic cerebral infarction. The patients were divided into 2 groups according to whether mortality occurred within one month. Values for NIHSS, stroke volume, Glasgow Coma Scale, and blood parameters were compared between the groups.Results:Values for Glasgow Coma Scale p=0.002, NIHSS p=0.001, stroke volume p=0.003, monocyte/HDL ratio p=0.047, neutrophils p=0.01, white blood cell p=0.007, calcium p=0.016, and albumin p=0.027 were statistically significant for the prediction of one-month mortality. There were no significant differences between the groups for other parameters.Conclusion:The clinical, laboratory, and radiological findings individually provide significant support for the short-term prognosis of stroke. The evaluation of these results together can provide a clearer advance understanding of a prognosis to better manage the course of the disease and prevent death.

Stroke is the third most common cause of death for patients presenting to emergency departments worldwide.1 Thus, to foresee possible mortality and morbidity in stroke cases, adoption of the right treatment and follow-up approach is important.2 The quality of the health service in a hospital emergency department depends on the successful prediction of the course of the disease and the clinical picture that may arise. Being aware of the prognosis of the disease in advance is important not only for making optimal treatment decisions but also for correctly informing the patient and managing health expenditures.In the literature, clinical parameters such as C reactive protein (CRP), red cell distribution width (RDW), neutrophil/lymphocyte ratio, and routine blood parameters such as albumin, infarct volume on admission, and National Institutes of Health Stroke Scale (NIHSS) score have previously been defined for the prediction of mortality in stroke cases.2-5 Pro-brain natriuretic peptides and pro-atrial natriuretic peptides, 2 other biochemical parameters that are not among the routine blood parameters, have also been shown to be important markers of stroke prognosis.6,7This study aimed to evaluate the association of clinical, biochemical, and radiological parameters with one-month mortality in patients that presented to the emergency service and received a diagnosis of ischemic stroke.  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