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   2837篇
  免费   170篇
  国内免费   19篇
耳鼻咽喉   31篇
儿科学   88篇
妇产科学   64篇
基础医学   261篇
口腔科学   54篇
临床医学   281篇
内科学   589篇
皮肤病学   44篇
神经病学   129篇
特种医学   102篇
外科学   478篇
综合类   47篇
一般理论   7篇
预防医学   304篇
眼科学   104篇
药学   290篇
中国医学   26篇
肿瘤学   127篇
  2024年   8篇
  2023年   32篇
  2022年   105篇
  2021年   112篇
  2020年   83篇
  2019年   123篇
  2018年   139篇
  2017年   105篇
  2016年   112篇
  2015年   110篇
  2014年   143篇
  2013年   205篇
  2012年   254篇
  2011年   268篇
  2010年   140篇
  2009年   128篇
  2008年   178篇
  2007年   155篇
  2006年   144篇
  2005年   115篇
  2004年   91篇
  2003年   81篇
  2002年   55篇
  2001年   22篇
  2000年   12篇
  1999年   9篇
  1998年   12篇
  1997年   12篇
  1996年   9篇
  1995年   6篇
  1994年   6篇
  1993年   2篇
  1992年   7篇
  1991年   4篇
  1990年   4篇
  1989年   5篇
  1987年   5篇
  1986年   1篇
  1985年   2篇
  1984年   1篇
  1981年   1篇
  1980年   2篇
  1979年   3篇
  1978年   2篇
  1975年   5篇
  1973年   2篇
  1972年   1篇
  1971年   2篇
  1968年   1篇
  1963年   1篇
排序方式: 共有3026条查询结果,搜索用时 0 毫秒
11.
AIM: To compare the effect of extra-amniotic normal saline solution infusion on its own, and in combination with dexamethasone on the ripening of the cervix and induction of labor. METHODS: A double-blind randomized clinical trial study was performed at Akbar Abadi Teaching Hospital in Tehran, Iran, between March 2002 and March 2003 on 84 pregnant women at a gestational age of 40 weeks or more, and with a Bishop score 相似文献   
12.
In this paper, the finite element method was used to simulate the response of the scanning vibrating electrode technique (SVET) across an iron–zinc cut-edge sample in order to provide a deeper understanding of the localized corrosion rates measured using SVET. It was found that, if the diffusion layer was neglected, the simulated current density using the Laplace equation fitted the experimental SVET current density perfectly. However, the electrolyte was not perturbed by a vibrating SVET probe in the field, so a diffusion layer existed. Therefore, the SVET current densities obtained from the local conductivity of the electrolyte would likely be more representative of the true corrosion rates than the SVET current densities obtained from the bulk conductivity. To help overcome this difference between natural conditions and those imposed by the SVET experiment, a local electrolyte corrected conductivity SVET (LECC-SVET) current density was introduced, which was obtained by replacing the bulk electrolyte conductivity measured experimentally by the local electrolyte conductivity simulated using the Nernst−Einstein equation. Although the LECC-SVET current density did not fit the experimental SVET current density as perfectly as that obtained from the Laplace equation, it likely represents current densities closer to the true, unperturbed corrosion conditions than the SVET data from the bulk conductivity.  相似文献   
13.
Brain research is the most expanding interdisciplinary research that is using the state of the art techniques to overcome limitations in order to conduct more accurate and effective experiments. Drug delivery to the target site in the central nervous system (CNS) is one of the most difficult steps in neuroscience researches and therapies. Taking advantage of the nanoscale structure of neural cells (both neurons and glia); nanodrug delivery (second generation of biotechnological products) has a potential revolutionary impact into the basic understanding, visualization and therapeutic applications of neuroscience. Current review article firstly provides an overview of preparation and characterization, purification and separation, loading and delivering of nanodrugs. Different types of nanoparticle bioproducts and a number of methods for their fabrication and delivery systems including (carbon) nanotubes are explained. In the second part, neuroscience and nervous system drugs are deeply investigated. Different mechanisms in which nanoparticles enhance the uptake and clearance of molecules form cerebrospinal fluid (CSF) are discussed. The focus is on nanodrugs that are being used or have potential to improve neural researches, diagnosis and therapy of neurodegenerative disorders.  相似文献   
14.
15.
16.
Sleep disturbance and fatigue are frequent complaints during pregnancy and postpartum. We assessed the effectiveness of Lavender cream and footbath on sleep quality and fatigue in pregnancy and postpartum. In this trial, 141 women with sleep disturbance at 25–28 weeks gestation were recruited from public health centers in Tabriz, Iran, from May 2013 until January 2014 and randomized into one of three groups receiving: Lavender and footbath, Lavender alone, or placebo cream. Sleep quality was assessed using the Pittsburgh sleep quality index at the 4th and 8th weeks after intervention and the 6th week postpartum. Fatigue was assessed with the multidimensional assessment of fatigue scale at the 6th week after intervention and the 6th week postpartum. Repeated measures ANOVA and ANCOVA were used. Compared with the placebo group, the global sleep quality score post-intervention in pregnancy and the postpartum were significantly lower in the Lavender and footbath and the Lavender cream only groups. Fatigue in both intervention groups was significantly improved only at the 6th week postpartum. No statistically significant differences were observed between the two intervention groups. Lavender cream with or without footbath may improve sleep quality in pregnancy and postpartum.  相似文献   
17.
This study aimed to investigate dietary supplement use among Iranian adults in northern Iran. A cross-sectional study was undertaken on randomly selected men and women in Guilan province, northern Iran. The study population was parents of children and adolescents studying in schools. Totally, 1,425 women and 676 men were studied and data on age, body weight, height, educational level, and supplement use was gathered using a self-administrated questionnaire. These data showed that supplement use was related to sex, body mass index, and educational levels in both sexes. Most common supplements used in this population were Iron, calcium, multivitamin/multiminerals and fish oils. These results showed that 13.3, 3.4, 2.2, and 1.1 % of the study men used iron, calcium, multivitamin/multimineral, and fish oil, respectively. In women, 27.1, 10.7, 5.1, and 5.5 % used Iron, calcium, multivitamin/multimineral, and fish oil, respectively. More educated men and women and those with more healthy weight were more likely to use any dietary supplement than the less educated and overweight/obese men and women. This study showed that iron was the most common dietary supplement in this study middle aged Iranians. Using the other supplements was mostly related to age, educational level, and body weight status in this population. These data indicated that dietary supplement use was inversely related to some health-related behaviors and socioeconomic factors.  相似文献   
18.

Purpose

To evaluate the short and long term efficiency of catheter directed thrombolysis using recombinant tissue type plasminogin activator (r-TPA; Actilyse), in treating acute deep venous thrombosis of the lower limb.

Material and methods

Twenty-eight patients with acute lower limb deep venous thrombosis underwent treatment by direct intra clot injection of thrombolytic therapy; Actilyse.

Result

Thrombus lysis was completed in 23 (82.2%) of 28 patients, partial in 4 (14.3%) patients and not achieved in one (3.5%) patient. There was no major complication. There was no rethrombosis or post thrombotic syndrome in any of the treated 23 patients over the follow up period of one year.

Conclusion

The treatment of acute lower limb deep venous thrombosis using recombinant tissue type plasminogin activator (r-TPA; Actilyse), is safe, effective and achieves significantly better short and long term clinical outcome for patients.  相似文献   
19.
Wound management has progressed significantly over the last five decades. This emanates from a greater understanding of wound healing, technological progression and improved clinical and scientific research. There are currently a plethora of absorbent dressings on the wound care market which claim to have the ability to manage exudates whilst encouraging healing. However, it is becoming clear, from analysing randomised controlled trials, that some of these absorbent dressings are not meeting their expectations when applied in a clinical setting. Many clinicians now feel that there should be more focus, not only on a dressing's ability to manage exudate efficiently, but on a dressing's ability to proactively encourage healing and thus exudate reduction will ensue. This paper proposes to critically review modern and emerging absorbent wound care dressings used to manage exuding wounds and discuses some advances in this area.  相似文献   
20.
This article presents a decentralized optimal controller design technique for the frequency and power control of a coupled wind turbine and diesel generator. The decentralized controller consists of two proportional-integral (PI)-lead controllers which are designed and optimized simultaneously using a quasi-Newton based optimization technique, namely, Davidon–Fletcher–Powell algorithm. The optimal PI-lead controllers are designed in such a way that there are no communication links between them. Simulation results show the superior performance of the proposed controller with a lower order structure compared to the benchmark decentralized linear-quadratic Gaussian integral controllers of orders 4 and 11. It is also shown that the proposed controller demonstrates an effective performance in damping the disturbances from load and wind power, as well as a robust performance against the parameter changes of the power system.  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