全文获取类型
收费全文 | 676篇 |
免费 | 41篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 57篇 |
妇产科学 | 17篇 |
基础医学 | 113篇 |
口腔科学 | 11篇 |
临床医学 | 54篇 |
内科学 | 154篇 |
皮肤病学 | 11篇 |
神经病学 | 26篇 |
特种医学 | 67篇 |
外科学 | 109篇 |
综合类 | 9篇 |
预防医学 | 25篇 |
眼科学 | 14篇 |
药学 | 38篇 |
中国医学 | 1篇 |
肿瘤学 | 25篇 |
出版年
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 17篇 |
2013年 | 21篇 |
2012年 | 33篇 |
2011年 | 24篇 |
2010年 | 28篇 |
2009年 | 20篇 |
2008年 | 23篇 |
2007年 | 26篇 |
2006年 | 24篇 |
2005年 | 26篇 |
2004年 | 17篇 |
2003年 | 26篇 |
2002年 | 13篇 |
2001年 | 20篇 |
2000年 | 14篇 |
1999年 | 11篇 |
1998年 | 22篇 |
1997年 | 22篇 |
1996年 | 22篇 |
1995年 | 16篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 16篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 11篇 |
1988年 | 15篇 |
1987年 | 10篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1974年 | 10篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1970年 | 8篇 |
1966年 | 6篇 |
排序方式: 共有732条查询结果,搜索用时 281 毫秒
41.
Parecoxib sodium, the injectable prodrug of valdecoxib, is a cyclooxygenase-2-specific inhibitor that is effective in the treatment of postoperative pain. In this randomized, double-blind, placebo-controlled study, we compared the efficacy of a single dose of parecoxib sodium 40 mg IM with single doses of morphine 6 and 12 mg IM in treating postoperative pain after gynecologic surgery requiring a laparotomy incision. By nearly all efficacy measures (including total pain relief and patient's global evaluation of study medication), parecoxib sodium 40 mg IM demonstrated pain relief and a decrease in pain intensity that was statistically similar to that with morphine 12 mg IM and superior to that with morphine 6 mg IM. Parecoxib sodium 40 mg IM-treated patients also demonstrated a longer time to use of rescue medication than patients treated with both morphine doses, and this dose provided sustained pain relief over the 12-h study period. The incidence of adverse events in the active treatment groups was similar to that observed with placebo. Parecoxib sodium, 40 mg IM, has been shown to be as effective as clinically relevant doses of morphine in patients after gynecologic laparotomy surgery. 相似文献
42.
Darbar D Warman EN Hammill SC Friedman PA;Worldwide Jewel AF Investigators 《Pacing and clinical electrophysiology : PACE》2005,28(10):1047-1051
BACKGROUND: Because the natural history of atrial tachyarrhythmia (AT) is not known in patients with implantable cardioverter-defibrillators (ICDs) but without device-based atrial therapies, we aimed to describe the characteristics and recurrence of AT in such patients. METHODS: In this multicenter trial, 269 patients with standard indications for ICD placement and 2 episodes of AT in the preceding year received a dual-chamber ICD capable of logging AT. Patients were randomly assigned to 3-month periods of atrial therapies "on" or "off." This analysis considered only the 118 patients with atrial therapies programmed off at ICD placement. RESULTS: Fifty-eight patients (49%) had at least 1 AT episode longer than 1 minute, and 21 (18%) had at least 1 prolonged episode (>24 hours). The median episode frequency for each patient (episodes per month) was 1.8 episodes longer than 1 minute, 0.8 longer than 1 hour, and 0 longer than 24 hours. The median AT burden was 12.2 hours per month. CONCLUSIONS: Patients with standard ICD indications and history of AT have infrequent episodes, frequent short episodes, or prolonged episodes of AT-atrial fibrillation. However, the clinical characteristics examined did not distinguish among the groups. Improved diagnostic tools may help identify patients at risk for development of AT, thereby allowing specific therapies to be targeted to each group of patients. 相似文献
43.
Role of tumour necrosis factor gene polymorphisms (-308 and -238) in breast cancer susceptibility and severity
下载免费PDF全文
![点击此处可从《Breast cancer research : BCR》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Azmy IA Balasubramanian SP Wilson AG Stephenson TJ Cox A Brown NJ Reed MW 《Breast cancer research : BCR》2004,6(4):R395-R400
Introduction
Genetic polymorphisms in the promoter region of the tumour necrosis factor (TNF) gene can regulate gene expression and have been associated with inflammatory and malignant conditions. We have investigated two polymorphisms in the promoter of the TNF gene (-308 G>A and -238 G>A) for their role in breast cancer susceptibility and severity by means of an allelic association study. 相似文献44.
BACKGROUND: This study examined the opioid-sparing effectiveness, analgesic efficacy, and tolerability of postoperative administration of the parenteral cyclooxygenase 2 selective inhibitor, parecoxib sodium, in total hip arthroplasty patients. METHODS: This was a multicenter, multiple-dose, randomized, double-blind, placebo-controlled study to compare the opioid-sparing effects, analgesic efficacy, and tolerability of postoperative 20 and 40 mg intravenous parecoxib sodium with placebo in hip arthroplasty patients. The first dose of study medication was administered after surgery with an intravenous bolus dose of 4 mg morphine when patients first requested pain medication; remedication with the study medication occurred at 12 and 24 h. Subsequent morphine doses (1-2 mg) were administered by patient-controlled analgesia. Efficacy was assessed by total morphine used, pain relief and pain intensity, time to last dose of morphine, and Global Evaluation rating of the study medication. RESULTS: Parecoxib sodium, 20 and 40 mg, reduced the total amount of morphine required over 36 h by 22.1% (56.5 mg morphine) and 40.5% (43.1 mg morphine), respectively, compared with placebo (72.5 mg morphine; P < 0.01). Patients receiving 20 and 40 mg parecoxib sodium experienced significantly greater maximum pain relief compared with those in the placebo group (P < 0.05). Patients who received 20 and 40 mg parecoxib sodium discontinued PCA morphine earlier than patients receiving placebo and had significantly higher Global Evaluation ratings. Parecoxib sodium, 40 mg, plus morphine demonstrated a significantly lower incidence of fever and vomiting compared with placebo plus morphine. CONCLUSIONS: Administration of parecoxib sodium with PCA morphine resulted in significantly improved postoperative analgesic management as defined by reduction in opioid requirement, lower pain scores, reduced time on PCA morphine, and higher Global Evaluation ratings. 相似文献
45.
The placental regulatory factor involved in the asymmetric IgG antibody synthesis responds to IL-6 features 总被引:4,自引:0,他引:4
Pregnancy success is attributed to the joint action of several factors such as regulatory placental molecules and components of the mother's immune system, among others. Asymmetrical glycosilated and functionally univalent IgG antibodies are suggested to influence the immune balance between the mother and foetus, playing a meaningful role on the foetal survival in the maternal uterus. Placental secretory factors might be responsible for the increase of these molecules during gestation. Since placental factors appeared to be the inducers of these high Concanavaline A-affinity (Con-A) IgG molecules our work was focused on the identification of such factors. The chromatographic separation of placental culture supernatants (PCS) allowed the detection of fractions capable of increasing the high Con-A affinity monoclonal antibody (Mab) ratio synthesised by a hybridoma. The presence of multimeric placental forms of interleukin 6 (IL-6) could be identified in these fractions. Considering that IL-6 modulates protein glycosylation we decided to investigate its effect on the monoclonal IgG glycosylation. When placental IL-6 containing fractions or rIL-6h were added to hybridoma cultures, the proportion of asymmetric IgG antibodies increased substantially. 相似文献
46.
47.
48.
Volumetric rendering techniques: applications for three-dimensional imaging of the hip 总被引:1,自引:0,他引:1
Fishman EK; Drebin B; Magid D; Scott WW Jr; Ney DR; Brooker AF Jr; Riley LH Jr; St. Ville JA; Zerhouni EA; Siegelman SS 《Radiology》1987,163(3):737-738
Volumetric rendering is a new approach to three-dimensional (3D) imaging that overcomes many of the drawbacks of currently available surface-rendering systems. Its application on the Pixar Imaging System in two cases of acetabular fracture was assessed to illustrate the features of the technique. The fast-computing architecture and large memory of this system allow rapid generation of a series of high-quality 3D images in each plane of rotation (x or spinal axis, z or somersaulting axis) that can be viewed as independent static images or as an animated real-time video loop. Editing to remove the normal contralateral hemipelvis enhances appreciation of acetabular abnormalities. Every pixel of computed tomographic data is preserved, allowing representation of both soft tissue and bone as translucent overlap. The presentation of data also allows detection of subtle abnormalities and features and minimizes the artifact generation common in surface-rendered images. 相似文献
49.
Edmondo Malan 《Anatomy and embryology》1934,103(4):409-437
Con 19 figure nel testo. 相似文献
50.
A sample from a population of dioptric powers may be used to estimate the distribution of dioptric powers in the population itself. This paper describes the method and shows further how one can obtain a graphical representation of the distribution. The graphical representation takes the form of ellipsoids of constant probability density. The centroid of each ellipsoid estimates the mean of the population while the size, shape and orientation show the extent and nature of the spread of the population. For illustrative purposes the theory is applied to measurements of refractive status before and after radial keratotomy. The ellipsoids are presented as stereo-pairs. They are useful for comparative and predictive purposes. Thus the ellipsoid that contains 95% of the population after surgery defines the set of refractive errors within which the refractive error of a particular eye can be expected to fall with a probability of 95%. 相似文献