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   600篇
  免费   21篇
耳鼻咽喉   15篇
儿科学   3篇
妇产科学   3篇
基础医学   68篇
口腔科学   19篇
临床医学   46篇
内科学   143篇
皮肤病学   15篇
神经病学   23篇
特种医学   7篇
外科学   79篇
综合类   3篇
预防医学   26篇
眼科学   2篇
药学   27篇
中国医学   1篇
肿瘤学   141篇
  2021年   10篇
  2020年   8篇
  2019年   10篇
  2018年   5篇
  2017年   10篇
  2016年   8篇
  2015年   7篇
  2014年   11篇
  2013年   13篇
  2012年   25篇
  2011年   29篇
  2010年   22篇
  2009年   11篇
  2008年   36篇
  2007年   31篇
  2006年   30篇
  2005年   22篇
  2004年   34篇
  2003年   28篇
  2002年   25篇
  2001年   24篇
  2000年   17篇
  1999年   33篇
  1998年   8篇
  1997年   7篇
  1996年   6篇
  1995年   5篇
  1994年   3篇
  1992年   15篇
  1991年   9篇
  1990年   7篇
  1989年   12篇
  1988年   6篇
  1987年   13篇
  1986年   12篇
  1985年   5篇
  1984年   4篇
  1983年   5篇
  1982年   3篇
  1979年   5篇
  1978年   5篇
  1977年   4篇
  1976年   2篇
  1975年   4篇
  1974年   5篇
  1973年   2篇
  1971年   7篇
  1969年   2篇
  1968年   4篇
  1967年   4篇
排序方式: 共有621条查询结果,搜索用时 0 毫秒
51.
52.
53.
OBJECTIVE: Recently, repeated home blood pressure (HBP) measurements in the morning for a long period have been shown to have a stronger predictive power for mortality in patients with hypertension than occasional casual/clinic blood pressure (CBP) measurements. We studied whether HBP in the morning in type 2 diabetic patients is useful for prediction of diabetic complications. RESEARCH DESIGN AND METHODS: The occurrence of diabetic complications (nephropathy, retinopathy, coronary heart disease [CHD], and cerebrovascular disease [CVD]) were examined in relation to morning HBP as well as to CBP in 170 type 2 diabetic patients treated with antidiabetic and antihypertensive drugs. Blood pressure was measured at the clinic during the day and at home after awakening in the morning. Clinic hypertension (CH) and morning hypertension (MH) were defined as systolic blood pressure (SBP) > or =130 mmHg and/or diastolic blood pressure (DBP) > or =85 mmHg. The relation of CH and MH to the prevalence of these events was examined. RESULTS: There were no significant differences in the prevalence of nephropathy, retinopathy, CHD, and CVD between the two groups with (n = 131) and without CH (n = 39), whereas the prevalences of these events in the patients with MH (n = 97) were significantly higher (P < 0.05) than in those without MH (n = 73). The prevalence of nephropathy was highly associated with systolic MH. CONCLUSIONS: Elevations of HBP in the morning in diabetic patients are strongly related to microvascular and macrovascular complications, especially nephropathy. It is concluded that the control of MH may prevent vascular complications in type 2 diabetic patients.  相似文献   
54.
To determine the population at high risk of nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) on hospital patients admission, a nasal swab was taken from the following patients: (1) those aged 70 years or over (age 70), (2) non ambulatory receiving regular home visits by nurses and physicians (visiting), (3) residents of nursing homes (nursing home), (4) patients from other hospitals (another Hp), and (5) those scheduled for surgery (presurgery). Between March and July 2000, a total of 412 patients were admitted and 136 were enrolled. MRSA was isolated from 12 (8.8%) patients. The number of patients positive for MRSA in the five groups, age 70, visiting, nursing home, another Hp, and presurgery, were 3 of 68, 3 of 21, 2 of 3, 3 of 9, and 1 of 35, respectively. Multivariate analysis revealed that living in a nursing home [odds ratio (OR) = 32.82, P = 0.010] or coming from another hospital (OR = 14.55, P = 0.0043) were high risk factors with for nasal carriage of MRSA. Furthermore, patients ages were further divided into three categories, 79, 80–89, 90, and regarded as independent high risk factors (OR = 3.08, P = 0.043). The results were that advanced living in a age (80, 90), living in a nursing home or coming from another hospital are high risk factors of nasal carriage of MRSA on hospital admission.  相似文献   
55.
The reconstruction of neuron morphology allows to investigate how the brain works, which is one of the foremost challenges in neuroscience. This process aims at extracting the neuronal structures from microscopic imaging data. The great advances in microscopic technologies have made a huge amount of data available at the micro-, or even lower, resolution where manual inspection is time consuming, prone to error and utterly impractical. This has motivated the development of methods to automatically trace the neuronal structures, a task also known as neuron tracing. This paper surveys the latest neuron tracing methods available in the scientific literature as well as a selection of significant older papers to better place these proposals into context. They are categorized into global processing, local processing and meta-algorithm approaches. Furthermore, we point out the algorithmic components used to design each method and we report information on the datasets and the performance metrics used.  相似文献   
56.
The aim of the present study was to investigate whether CYP2C19 polymorphism status and gastric emptying are related to healing in patients with gastric ulcers. We studied the CYP2C19 status in seven patients with proton pump inhibitor (PPI)-resistant ulcers, 21 with PPI-sensitive ulcers and 46 healthy volunteers using polymerase chain reaction restriction fragment length polymorphism to detect CYP2C19m1 mutation in exon 5 and CYP2C19m2 mutation in exon 4. Gastric emptying was evaluated using the 13C-acetate breath test. The frequency of phenotypes, indicated by genotypes, did not differ significantly between the three patient groups. The peak time of 13C excretion in patients with PPI-resistant ulcers was significantly longer than that of patients with PPI-sensitive ulcers and healthy volunteers. Our results suggest that rate of gastric emptying, but not CYP2C19 polymorphism, is likely to be an important factor in the delayed healing of patients with PPI-resistant gastric ulcer.  相似文献   
57.
58.
59.

Purpose  

We conducted this randomized trial to compare the LigaSure Vessel Sealing System with conventional methods in gastrointestinal carcinoma surgery at five specialty cancer hospitals.  相似文献   
60.
In this study, we examined the capacity of the Porcine Corneal Ocular Reversibility Assay (PorCORA) to classify the reversibility of ocular effects for 32 test compounds (20 reversible, 12 irreversible) from various chemical classes. PorCORA predicted 28 of 32 compounds correctly when compared to historical rabbit eye test data. The correlation coefficient for PorCORA versus historical rabbit test data was 0.84, based on the last day of damaged cornea reversal. These results demonstrate a high correlation between corneal irritation recovery time in the PorCORA and the rabbit eye. When compared to historical Modified Maximal Average Score (MMAS) in rabbit eyes, PorCORA yielded a correlation coefficient of 0.80, demonstrating ability to predict MMAS. PorCORA was highly predictive of regulatory agency ocular hazard classification categories, resulting in 91% accuracy for EU R41 and GHS Category 1. PorCORA was also predictive of EPA Category I (88% accuracy). Overall, the accuracy (88–91%), sensitivity (79–86%), specificity (94%), positive predictivity (94%), and negative predictivity (85–89%) for all three regulatory classifications indicate that ocular irritation hazardous effects were well predicted by the PorCORA. This study suggests that PorCORA could help discriminate between EU R36 and R41, GHS Categories 1 and 2, and EPA Categories I and II.  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