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   5588篇
  免费   546篇
  国内免费   144篇
耳鼻咽喉   34篇
儿科学   56篇
妇产科学   26篇
基础医学   512篇
口腔科学   131篇
临床医学   766篇
内科学   531篇
皮肤病学   28篇
神经病学   238篇
特种医学   228篇
外科学   393篇
综合类   987篇
预防医学   440篇
眼科学   108篇
药学   401篇
  1篇
中国医学   1251篇
肿瘤学   147篇
  2024年   17篇
  2023年   67篇
  2022年   187篇
  2021年   265篇
  2020年   231篇
  2019年   201篇
  2018年   175篇
  2017年   232篇
  2016年   250篇
  2015年   232篇
  2014年   471篇
  2013年   358篇
  2012年   405篇
  2011年   454篇
  2010年   354篇
  2009年   279篇
  2008年   226篇
  2007年   210篇
  2006年   196篇
  2005年   170篇
  2004年   147篇
  2003年   140篇
  2002年   127篇
  2001年   113篇
  2000年   94篇
  1999年   80篇
  1998年   72篇
  1997年   68篇
  1996年   68篇
  1995年   63篇
  1994年   49篇
  1993年   36篇
  1992年   39篇
  1991年   31篇
  1990年   27篇
  1989年   13篇
  1988年   15篇
  1987年   15篇
  1986年   12篇
  1985年   16篇
  1984年   14篇
  1983年   13篇
  1982年   7篇
  1981年   10篇
  1980年   10篇
  1979年   3篇
  1978年   6篇
  1977年   4篇
  1976年   3篇
  1975年   2篇
排序方式: 共有6278条查询结果,搜索用时 15 毫秒
81.

Objective

To evaluate the current evidence of the effectiveness of dry needling of myofascial trigger points (MTrPs) associated with low back pain (LBP).

Data Sources

PubMed, Ovid, EBSCO, ScienceDirect, Web of Science, Cochrane Library, CINAHL, and China National Knowledge Infrastructure databases were searched until January 2017.

Study Selection

Randomized controlled trials (RCTs) that used dry needling as the main treatment and included participants diagnosed with LBP with the presence of MTrPs were included.

Data Extraction

Two reviewers independently screened articles, scored methodologic quality, and extracted data. The primary outcomes were pain intensity and functional disability at postintervention and follow-up.

Data Synthesis

A total of 11 RCTs involving 802 patients were included in the meta-analysis. Results suggested that compared with other treatments, dry needling of MTrPs was more effective in alleviating the intensity of LBP (standardized mean difference [SMD], ?1.06; 95% confidence interval [CI], ?1.77 to ?0.36; P=.003) and functional disability (SMD, ?0.76; 95% CI, ?1.46 to ?0.06; P=.03); however, the significant effects of dry needling plus other treatments on pain intensity could be superior to dry needling alone for LBP at postintervention (SMD, 0.83; 95% CI, 0.55–1.11; P<.00001).

Conclusions

Moderate evidence showed that dry needling of MTrPs, especially if associated with other therapies, could be recommended to relieve the intensity of LBP at postintervention; however, the clinical superiority of dry needling in improving functional disability and its follow-up effects still remains unclear.  相似文献   
82.
83.
Summary Cytological diagnosis of pancreatic carcinoma sometimes poses difficulties in distinguishing malignant from benign cells. Recent molecular study of pancreatic carcinoma has revealed a very high incidence of a point mutation of the c-Ki-ras oncogene at codon 12 in this neoplasm. To take advantage of this technique for the diagnosis of pancreatic carcinoma, we attempted to amplify the c-Ki-ras gene from endoscopically obtained pancreatic juice by isolation of DNA and polymerase chain reaction (PCR) coupled with restriction fragment length polymorphism (RFLP). PCR was possible in approx 70% of the cases. A point mutation was nonradioisotopically detected in 4 of 6 pancreatic carcinomas and in one intraductal papillary neoplasm, whereas no mutation was detected in other cases. Thus, this method was thought to be useful for the diagnosis of pancreatic carcinoma.  相似文献   
84.
85.
IntroductionLabor pain is one of the most intensive pains experienced by women; it results in physical, emotional, and physiological changes in women’s body. The present study aimed to examine the effect of GB21 acupressure on labor pain.DesignIn this randomized clinical trial, 174 primiparous women in their first stage of labor were selected and assigned to three groups: GB21 acupressure group (n = 58), sham group (n = 58), and control group (n = 58).InterventionsThe acupressure and sham groups received routine labor care and acupressure in three different phases of cervical dilations to 3−5 cm, 6−7 cm, and 8−10 cm. The control group received routine care in labor.Main outcome measuresPain severity was measured using a pain scale ruler in three cervical dilations before and after intervention. The collected data were analyzed using the ANOVA, Kruskal–Wallis, paired-t test and Mann–Whitney tests.ResultsPain reduction was significantly higher in GB21 groups compared with sham and control groups (P = 0.001). No statistically significant difference was observed between the three groups in terms of delivery outcomes.ConclusionsIn this study, GB21 acupressure was effective in pain relief during labor, hence recommended as a practical, effective, inexpensive, and accessible method for labor pain management.  相似文献   
86.
2-Hydroxy-3-butoxypropyl hydroxyethyl celluloses (HBPEC), which are thermoresponsive polymers, are prepared by grafting butyl glycidyl ether onto hydroxyethyl cellulose. The effects of several factors on the cloud point (Tc) of the HBPEC are also investigated. The Tc of HBPEC can be tuned to a ranging from 17.0 to 43.0 °C by changing the molar substitution of hydrophobic groups. Increasing the concentration of HBPEC leads to a faster phase transition as well as a corresponding linear decrease in the Tc. A series of salts with common anions or cations are used to investigate the effects of specific anions or cations on the Tc of HBPEC aqueous solutions. It is discovered that the Tc of HBPEC is largely influenced by the variation of cation identity and concentration. Plotting Tc as a function of cation activity shows that the Tc can be classified by charge density.  相似文献   
87.
This paper presents a general embedded processing system implemented in a field-programmable gate array providing high frame rate and high accuracy for a laser Doppler blood flow imaging system. The proposed system can achieve a basic frame rate of flow images at 1 frame/second for 256×256 images with 1024 fast Fourier transform (FFT) points used in the processing algorithm. Mixed fixed-floating point calculations are utilized to achieve high accuracy but with a reasonable resource usage. The implementation has a root mean square deviation of the relative difference in flow values below 0.1% when compared with a double-precision floating point implementation. The system can contain from one or more processing units to obtain the required frame rate and accuracy. The performance of the system is significantly higher than other methods reported to date. Furthermore, a dedicated field-programmable gate array (FPGA) board has been designed to test the proposed processing system. The board is linked with a laser line scanning system, which uses a 64×1 photodetector array. Test results with various operating parameters show that the performance of the new system is better, in terms of noise and imaging speed, than has been previously achieved.  相似文献   
88.
89.
This review provides a summary statement of recommended implementations of arterial spin labeling (ASL) for clinical applications. It is a consensus of the ISMRM Perfusion Study Group and the European ASL in Dementia consortium, both of whom met to reach this consensus in October 2012 in Amsterdam. Although ASL continues to undergo rapid technical development, we believe that current ASL methods are robust and ready to provide useful clinical information, and that a consensus statement on recommended implementations will help the clinical community to adopt a standardized approach. In this review, we describe the major considerations and trade‐offs in implementing an ASL protocol and provide specific recommendations for a standard approach. Our conclusion is that as an optimal default implementation, we recommend pseudo‐continuous labeling, background suppression, a segmented three‐dimensional readout without vascular crushing gradients, and calculation and presentation of both label/control difference images and cerebral blood flow in absolute units using a simplified model. Magn Reson Med 73:102–116, 2015. © 2014 Wiley Periodicals, Inc.  相似文献   
90.
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