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   1888篇
  免费   84篇
  国内免费   10篇
耳鼻咽喉   14篇
儿科学   55篇
妇产科学   35篇
基础医学   216篇
口腔科学   23篇
临床医学   215篇
内科学   389篇
皮肤病学   19篇
神经病学   77篇
特种医学   37篇
外国民族医学   3篇
外科学   349篇
综合类   51篇
一般理论   6篇
预防医学   95篇
眼科学   80篇
药学   189篇
中国医学   18篇
肿瘤学   111篇
  2024年   1篇
  2023年   23篇
  2022年   83篇
  2021年   88篇
  2020年   54篇
  2019年   81篇
  2018年   90篇
  2017年   52篇
  2016年   67篇
  2015年   57篇
  2014年   106篇
  2013年   110篇
  2012年   152篇
  2011年   189篇
  2010年   105篇
  2009年   70篇
  2008年   114篇
  2007年   120篇
  2006年   83篇
  2005年   84篇
  2004年   84篇
  2003年   62篇
  2002年   55篇
  2001年   4篇
  2000年   11篇
  1999年   8篇
  1998年   5篇
  1997年   5篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   2篇
  1989年   1篇
  1988年   2篇
  1987年   1篇
  1984年   1篇
  1983年   3篇
  1972年   2篇
  1969年   1篇
  1962年   1篇
  1961年   1篇
  1960年   1篇
排序方式: 共有1982条查询结果,搜索用时 15 毫秒
21.
Recent advances in the understanding of the pathophysiology, aggressive treatment, and early detection of rheumatoid arthritis (RA) have changed the clinical, pathologic, and functional outcomes in patients with RA. Early aggressive treatment of RA has now become the norm in clinical practice rather than the use of the traditional pyramid approach of the last half of the twentieth century. Early treatment with monotherapy of traditional disease-modifying antirheumatic drugs (DMARDs) or biologics, combination traditional DMARD therapy and, especially, combination of biologic therapy and methotrexate, have revolutionized the treatment of RA, producing significant improvement in clinical, radiographic, and functional outcomes not seen previously. For the individual patient, we still cannot determine which medication or combination of medications will give the most complete response. There have been a number of recent, well-designed clinical trials that have tried to answer this question. Herein we review the evidence-based medicine that addresses these issues.  相似文献   
22.
Quantitative determination of gatifloxacin in tablets, solid lipid nanoparticles (SLNs) and eye-drops using a very simple and rapid chromatographic technique was validated and developed. Formulations were analyzed using a reverse phase SUPELCO® 516 C-18-DB, 50306-U, HPLC column (250 mm × 4.6 mm, 5 μm) and a mobile phase consisting of disodium hydrogen phosphate buffer:acetonitrile (75:25, v/v) and with orthophosphoric acid pH was adjusted to 3.3 The flow rate was 1.0 mL/min and analyte concentrations were measured using a UV-detector at 293 nm. The analyses were performed at room temperature (25 ± 2 °C). Gatifloxacin was separated in all the formulations within 2.767 min. There were linear calibration curves over a concentration range of 4.0–40 μg.mL−1 and correlation coefficients of 0.9998 with an average recovery above 99.91%. Detection of analyte from different dosage forms at the same Rt indicates the specificity and stability of the developed method.  相似文献   
23.
24.

Purpose of Review

The purpose of this review is to highlight recent hardware and software advances in coronary computed tomography angiography (CTA) that make it a potentially viable alternative to invasive coronary angiography for surveillance of cardiac allograft vasculopathy (CAV) in heart transplant recipients.

Recent Findings

Dual-source CT, multisegment reconstruction, and intracycle motion correction algorithms are all technologies applied during or after image acquisition that can improve image quality and diagnostic accuracy in patients with elevated heart rates, such as heart transplant recipients. CT fractional flow reserve may also add value in this clinical scenario.

Summary

Coronary CTA now has equivalent diagnostic accuracy, offers more nuanced anatomic information, is inherently safer, and could be less costly than invasive coronary angiography. For these reasons, coronary CTA may now be a viable alternative to ICA for CAV surveillance in heart transplant recipients.
  相似文献   
25.
Metabolic Brain Disease - Thymoquinone (Tq), an active compound of Nigella sativa, has been known for its anti-inflammatory, antioxidant, and neuroprotective characteristics. The present study is...  相似文献   
26.
Multiple myeloma (MM) is associated with amyloidosis in approximately 15% of the patients. The most frequent presenting signs of such an association are nephrotic syndrome, cardiomyopathy and peripheral neuropathy. Amyloid arthropathy is not a frequent feature. We report a patient with immunoglobulin D (IgD) lambda type MM with presenting symptoms related to mucocutaneous amyloidosis and also amyloid arthropathy. He had no clinical and laboratory involvement due to nephrotic syndrome or cardiomyopathy. IgD myeloma is a rare form of MM and therefore much of the information about the disease is derived from case reports describing patients with associated symptoms. Our case also shows an unusual organ distribution of amyloid.  相似文献   
27.
Emergency Radiology - Neonatal herpes simplex virus (HSV) infection of the central nervous system (CNS) is an emergency that can have devastating structural consequences and clinical outcomes. As...  相似文献   
28.
Tandem configuration-containing perovskite and silicon solar cells are promising candidates for realizing a high power conversion efficiency of 30% at reasonable costs. Silicon solar cells with planar front surfaces used in tandem devices cause high optical losses, which significantly affects their efficiency. Moreover, some studies have explored the fabrication of perovskites on textured silicon cells. However, due to improper texturing, light trapping is not ideal in these devices, which reduces the efficiency. In this work, we optimized the pyramid height of textured silicon cells and efficiently characterized them to achieve enhanced light trapping. Two different kinds of perovskites, namely, Cs0.17FA0.6Pb(Br0.17I0.7)3 and Cs0.25FA0.6Pb(Br0.20I0.7)3 with wide bandgaps were conformally deposited on textured silicon cells, and the performance of these flat and fully textured tandem devices was numerically analyzed. The thickness of each layer in the tandem cell was optimized in a way to ensure a perfect current match between the top perovskite and bottom silicon subcells. The results indicated that the textured tandem configuration enhances light absorption over a broad spectral range due to the optimized pyramid height compared to flat surfaces. Eventually, the photovoltaic parameters of the proposed tandem cell were compared with the already existing structures, and our design supports large values of open circuit voltage (Voc) = 1.78 V, short circuit current density (Jsc) = 20.09 mA cm−2, fill factor (FF) = 79.01%, and efficiency (η) = 28.20% compared to other kinds of tandem solar cells.

Tandem configuration-containing perovskite and silicon solar cells are promising candidates for realizing a high power conversion efficiency of 30% at reasonable costs.  相似文献   
29.
Digital microfluidic (DMF) platforms have contributed immensely to the development of multifunctional lab-on-chip systems for performing complete sets of biological and analytical assays. Electrowetting-on-dielectric (EWOD) technology, due to its outstanding flexibility and integrability, has emerged as a promising candidate for such lab-on-chip applications. Triggered by an electrical stimulus, EWOD devices allow precise manipulation of single droplets along the designed electrode arrays without employing external pumps and valves, thereby enhancing the miniaturization and portability of the system towards transcending important laboratory assays in resource-limited settings. In recent years, the simple fabrication process and reprogrammable architecture of EWOD chips have led to their widespread applications in food safety analysis. Various EWOD devices have been developed for the quantitative monitoring of analytes such as food-borne pathogens, heavy metal ions, vitamins, and antioxidants, which are significant in food samples. In this paper, we reviewed the advances and developments in the design of EWOD systems for performing versatile functions starting from sample preparation to sample detection, enabling rapid and high-throughput food analysis.  相似文献   
30.
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